gap closing - edugains · gap closing comparing fractions junior / intermediate facilitator's...

21
GAP CLOSING Comparing Fracons Junior / Intermediate Facilitator's Guide

Upload: phungthuy

Post on 09-Dec-2018

316 views

Category:

Documents


1 download

TRANSCRIPT

Page 1: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

Gap ClosinG

Comparing Fractions

Junior / intermediateFacilitator's Guide

Page 2: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire
Page 3: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

Module 2

Comparing Fractions

Diagnostic .........................................................................................4

Administer the diagnostic ......................................................................4

Using diagnostic results to personalize interventions ............................4

Solutions ................................................................................................5

Using Intervention Materials ......................................................6

Comparing Fractions Using Pictures ..........................................................7

Comparing Fractions with the Same Denominator .................................... 11

Comparing Fractions with the Same Numerator ........................................13

Equivalent Fractions ...............................................................................15

Comparing Fractions to 1 _ 2 and to 1 ...........................................................18

Page 4: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

3 © Marian Small, 2010 Comparing Fractions

CoMparIng FraCtIons

relevant Learning Expectation for grade 6… compare, and order fractional amounts with unlike denominators, including proper and improper fractions and mixed numbers, using a variety of tools (e.g., fraction circles, Cuisenaire® rods, drawings, number lines, calculators) and using standard fractional notation

possible reasons a student might struggle in comparing fractions or deciding if they are equalMany students struggle with comparing fractions and/or determining their equivalence. Some of the problems include:• notrealizingthatyoumayhavetoreorientonediagramtomatchanothertodeterminewhichfraction

is greater (e.g., thinking that 2 _ 3 < 3 _

5 since the blue is farther to the right with 3 _ 5 )

• notrealizingthatyoucanonlycomparevisuallyifthefractionsrefertothesamewhole• notrealizingthatiffractionsarecloseinsize,hand-drawndiagramsmaynotbeausefultool,e.g.to

compare 3 _ 8 and 4 _

10

• notrecognizingthatnumeratorsareallthatmatterwhencomparingfractionswiththesamedenominator

• assumingthatiffractionshavethesamenumerator,thegreateronehasthegreaterdenominator• showingmorediscomfortwhencomparingimproperfractionsthanwhencomparingproperfractions• thinkingthatifbothnumeratoranddenominatorarelarger,thefractionisautomaticallylarger

(e.g., thinking that 7 _ 10 > 4 _

5 since 7 and 10 are more than 4 and 5)• notrealizingthatfractionsareequalonlyifnumeratoranddenominatoraremultipliedordividedby

the same amount, not if the same amount is added or subtracted• thinkingthat4 _

6 > 2 _ 3 since a picture of 4 out of 6 items shows more items than a picture of 2 out of

3 items• notrealizingthatcomparisonstothebenchmarksof1 _

2 and 1 are often an easy way to compare fractions and that this can be done simply by comparing the numerator to the denominator

Part-of-wholemodelsareusedtoclosethegapinstudentunderstandingaboutfractionalcomparisonsandequivalenceratherthanpart-of-setmodelsbecausethelatterrequiresmoresophistication.Althoughstudentscouldfigureoutwhy,forexample,2 _

3 of 12 is greater than 1 _ 2 of 12 by determining

thecountforeach,itwouldbemuchmoredifficulttoseewhy2 _ 3 of 11 is greater than 1 _

2 of 11. For this reason, parts of wholes are used; parts of measures could also be used.

additional considerationBefore beginning the diagnostic or using the intervention materials, students need to know that > means “greater than” and < means “less than.” Post a reminder as reference.

Page 5: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

4 © Marian Small, 2010 Comparing Fractions

DIagnostIC

administer the diagnosticIf students need help in understanding the directions of the diagnostic, clarify an item’s intent.

If available, students can use concrete fraction pieces instead of the pictorial models provided in the templates. However, after Question 1, the purpose is to see how students work symbolically. If they are dependent on the materials for many questions, assume that they need the relevant intervention materials.

Using the diagnostic results to personalize interventionsProvide Template 1 for students to use if needed.Intervention materials are included for each of these topics:• comparingfractionsusingpictures• comparingfractionswiththesamedenominator• comparingfractionswiththesamenumerator• equivalentfractions• comparingfractionsto1 _

2 and 1

You can use all or only part of these sets of materials, based on student performance with the diagnostic.

Evaluating Diagnostic Results Suggested Intervention MaterialsIf students struggle with Question 1 Use Comparing Fractions using Pictures

If students struggle with Questions 2a, 3a, b, c

Use Comparing Fractions with the Same Denominator

If students struggle with Questions 2b, c, 3d, e, 4e

Use Comparing Fractions with the Same Numerator

If students struggle with Questions 1c, 5, 6

Use Equivalent Fractions

If students struggle with Questions 2b, d, 3f–h, and 4

Use Comparing Fractions to 1 _ 2 and 1

Materials• FractionCirclesandRectangles(1)template

Comparing Fractions © Marian Small, 2010 3

Diagnostic

1. Circle the greater shaded amount. If the fractions are equal, circle both.

a) b)

c) d)

2. Circle the greater fraction. Tell why it is greater.

a)7––12

5––12 because

b)3–4

3–2 because

c)5–6

5–8 because

d)4–6

1–3 because

3. Circle all of the fractions below that are greater than2–5.

a)4–5 b)

1–5 c)

5–5 d)

2–3 e)

2–7 f)

8–3 g)

20––6 h)

7–8

4 © Marian Small, 2010 Comparing Fractions

Diagnostic (Continued)

4. Circle all of the fractions below that are between 0 and1–2.

a)2–5 b)

5–6 c)

4–9 d)

2–3 e)

1––10 f)

4–7

5. Circle the fractions below that are equivalent (equal) to4–6.

a)2–3 b)

3–5 c)

5–7 d)

20––30 e)

32––48

6. Complete the statement: The best way to create an equivalent fraction

to3–5 is to

20 © Marian Small, 2010 Comparing Fractions

Fraction Circles and Rectangles (1)

1–3

1–4

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––121––

121––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1–8

1–6

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–3

1–3

1–3

1–3

1–3

1–3

1–3

1–3

1–31–

31–3

Page 6: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

5 © Marian Small, 2010 Comparing Fractions

solutions1. a)

b)

c)

d)

2. a) 7 _ 12 e.g., because the pieces are the same size but there are more of them;

(students may draw pictures and show that 7 _ 12 uses more space, but the

wholesmust be the same size)b) 3 _

2 e.g., because 3 _ 2 is more than 1 and 3 _

4 is less than 1c) 5 _

6 e.g.,becausethereare5pieceseachtimebutsixthsarebiggerthaneighthsd) 4 _

6 e.g., because 4 _ 6 is more than 1 _

2 and 1 _ 3 is less than 1 _

2

3. a, c, d, f, g, h

4. a, d, e

5. e.g., draw a picture of 3 out of 5 and keep making more rows, etc.

6. a, c, e

Page 7: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

6 © Marian Small, 2010 Comparing Fractions

UsIng IntErVEntIon MatErIaLs

The purpose of the suggested student work is to help them build a foundation with comparing fractions that they can use with ratios, percents, and decimals as they move into Grade 7.

Eachsetofinterventionmaterialsincludesasingle-taskOpenQuestionapproachandamultiple-questionThinkSheetapproach.Theseapproachesbothaddressthesamelearning goals, and represent different ways of engaging and interacting with learners. Youcouldassignjustoneoftheseapproaches,orsequencetheOpenQuestionapproach before, or after the Think Sheet approach.

Suggestions are provided for how best to facilitate learning before, during, and after usingyourchoiceofapproaches.Thisthree-partstructureconsistsof:• Questionstoaskbeforeusingtheapproach• Usingtheapproach• Consolidatingandreflectingontheapproach

Page 8: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

7 © Marian Small, 2010 Comparing Fractions

Comparing Fractions Using picturesLearning Goal•reasoningabouthowtwofractionsshownpictoriallycanbecompared.

open Question

Questions to Ask Before Using the Open QuestionPlaceabluepatternblockrhombusontopofahexagonandbesideitapatternblocktriangleontopofahexagon.Ask:◊What fraction of the hexagon is each shape? ( 1 _

3 and 1 _ 6 )

◊Which fraction is greater? How can you be sure? ( 1 _ 3 since it takes up more space; I

can be sure by putting the triangle right on top of it to show it’s smaller)

Placetherhombusindifferentpositionsonthehexagon.◊Does where I put the fraction change its size? (no)◊Suppose I had a picture of two fractions. How could I compare them to see which

took up more space? (e.g., cut one out and put it on top of the other)◊Why do the wholes have to be the same size if you’re comparing the fractions?

(e.g., even a little part of something really big is a lot more than a big part of something really little)

Using the Open QuestionProvide the templates of circle and rectangle models for fractions.

ExplainthattheyaretouseonlycirclesforQuestion1andonlyrectanglesforQuestion 2.

By viewing or listening to student responses, note if they:• use visual estimates when appropriate (when fractions are easily compared

visually)• appropriately match to compare when the comparison is not as obvious

Dependingonstudentresponses,useyourprofessionaljudgementtoguidespecificfollow-up.

Consolidating and Reflecting on the Open QuestionObservethecomparisonsstudentsmadeandthestrategiestheyused.Ask:◊Why was it easy to see that 1 _

10 was the smallest? (e.g., It took up hardly any space)◊When did you turn the circles to line things up to compare the fractions? Why?

(e.g., for 5 _ 6 and 9 _

10 since they didn’t start at the same place)◊Which fractions were really close in size? Was it hard to compare them even when

you moved the fraction? (e.g., 2 _ 3 and 7 _

10 -Ithink7

_ 10 was more but it was so close, I’m

not sure)◊When you are ordering a whole set of fractions, what’s a good strategy for starting?

(e.g., start with really tiny ones at one end and really big ones at the other end and then compare two at a time in the middle)

Materials• FractionCirclesandRectangles(1)(2)templates

• patternblocks

Comparing Fractions © Marian Small, 2010 21

Fraction Circles and Rectangles (2)1.

2.

1–6

1–6

1–6

1–6

1–6

1–6

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–5 1–

5

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––101––

101––

10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–3

1–3

1–3

1–3

1–3

1–3

Comparing Fractions © Marian Small, 2010 5

Comparing Fractions Using pictures

open Question

1. Choose 4 of the 6 fraction circles to put in order from least to greatest.

Describe your strategies.

2. Choose 4 of the 6 fraction rectangles to put in order from least to greatest.

Describe your strategies.

20 © Marian Small, 2010 Comparing Fractions

Fraction Circles and Rectangles (1)

1–3

1–4

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––121––

121––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1––12

1–8

1–6

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–3

1–3

1–3

1–3

1–3

1–3

1–3

1–3

1–31–

31–3

Page 9: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

8 © Marian Small, 2010 Comparing Fractions

solutionsCircles: Students show only 4 of these circle fractions:

1 ___ 10 1 __ 4 2 __ 5 3 __ 4 5 __ 6 9 ___ 10

Sample strategies:

1 _ 10 is very tiny so I knew it was least.

I overlapped 5 _ 6 and 2 _

5 and 2 _ 5 was less.

I could see that 9 _ 10 was the most since it was almost the whole thing.

rectangles: Students show only 4 of these rectangle fractions:

Sample strategies:

1 _ 10 is very tiny so I knew it was least.

I overlapped 2 _ 3 and 7 _

10 and 2 _ 3 was less

I could just see that 1 _ 3 < 2 _

3 .

1 ___ 10

1 __ 3

3 __ 5

5 __ 8

2 __ 3

7 ___ 10

Page 10: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

9 © Marian Small, 2010 Comparing Fractions

think sheet

Questions to Ask Before Assigning the Think SheetPlaceabluepatternblockrhombusontopofahexagonandbesideitapatternblocktriangleontopofahexagon.Ask:What fraction of the hexagon is each shape? ( 1 _

3 and 1 _ 6 )

◊Which fraction is greater? How can you be sure? (e.g., 1 _ 3 since it takes up more

space; I can be sure by putting the triangle right on top of it to show it’s smaller)

Placetherhombusindifferentpositionsonthehexagon.Ask:◊Does where I put the fraction change its size? (no)◊Suppose I had a picture of two fractions. How could I compare them to see which

took up more space? (e.g., cut one out and put it on top of the other)◊Why do the wholes have to be the same size if you’re comparing the fractions?

(e.g., even a little part of something really big is a lot more than a big part of something really little)

Using the Think SheetReadtheshadedintroductoryboxwiththestudents.

Make sure they understand that sometimes you can just “see” which fraction is more and at other times you have to cut out and rearrange.

Assign the tasks.

By viewing or listening to student responses, note if they:• can visually compare quickly, when appropriate• know how to rearrange visuals to compare, when that is needed• recognize that when only part of a whole is coloured, then it is easy to get greater

fractions by colouring in more parts

Depending on student responses, use your professional judgement to guide further follow-up.

Consolidating and Reflecting: Questions to Ask After Using the Think Sheet◊Why was it easy to answer Question 1? (e.g., You can just look to see 1 _

3 is not even 1 _

2 and 4 _ 5 is almost the whole thing.)

◊Why might someone think that Question 2 easier than Question 3? (e.g., The fractions were shaded starting at the same place at the top so it was easy to overlap them.)

◊Does your strategy change if the shape was a rectangle and not a circle? (e.g., no; I still had to turn things sometimes or fold them to compare them.)

◊Why is it easy to see that 7 _ 8 > 5 _

8 if you colour in 5 _ 8 of a shape? (just colour in two more

sections-ifyoucolourmore,thefractionisgreater)

6 © Marian Small, 2010 Comparing Fractions

Comparing Fractions Using pictures (Continued)

think sheet

Think of comparing two different fractions.

Each is a part of the same whole.

Sometimes, it’s just easy to see which is greater.

2–3 >

1–4 since

2–3 is more than half the circle and

1–4 is less and it’s easy

to see.

Sometimes we have to work a little harder. One fraction is greater than another if its picture has “extra” when we overlap them as much as possible.

For example,3–5 >

2–3 since we can move one fraction to overlap the

other and see that2–3 has a little extra.

Then

We can only use pictures to compare fractions if the fractions are parts of the same whole.

Comparing Fractions © Marian Small, 2010 7

Comparing Fractions Using pictures (Continued)

Circle the fraction that is greater.

1. 2.

4–5

1–3

4–5

3–4

3. 4.

5–6

3–5

5. 6.

7. Shade in 5–8 of a rectangle. How could you use pictures to show at least

six other fractions greater than5–8?

3–8

1–3

1–3

2–5

1–5

2–8

22 © Marian Small, 2010 Comparing Fractions

Pairs of Fractions1. 2.

3. 4.

5. 6.

7.

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–6

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–4

1–5

1–5

1–51–

5

1–5

1–5

1–5

1–51–

5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–5

1–51–

5

1–5

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1–8

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1––10

1–3

1–3

1–3

1–3

1–3

1–3

1–3

1–3

1–3

Materials• PairsofFractionstemplate

• patternblocks• colouredpencils

Page 11: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

10 © Marian Small, 2010 Comparing Fractions

solutions1. 4 _

5 2. 4 _

5 3. 5 _

6 4. 3 _

8 5. 2 _

5 6. 2 _

8 7. Sample responses:

I could see that 6 _ 8 ,

7

_ 8 and 8 _

8 were bigger by using the same rectangle since more of it would be used.

I could use the rectangle with 4 sections and colour 3 or 4 of them and line them up to see that 3 _

4 and 4 _ 4 are also bigger.

I lined up the rectangle in 6 sections underneath 5 _ 8 and saw that I would have to go to 4 _

6 to get another bigger fraction.

Page 12: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

11 © Marian Small, 2010 Comparing Fractions

Comparing Fractions with the same DenominatorLearning Goal•reasoningabouthowtwofractionswiththesamedenominatorcanbecompared.

open Question

Questions to Ask Before Using the Open QuestionAsk students to use pattern blocks to show 1 _

3 and then 2 _ 3 . Ask:

◊How do your models show why 2 _ 3 > 1 _

3 ? (e.g.,theycovermoreofthehexagon)◊Didyoufindthatsurprising?(no, 2 of something is more than 1 of it)◊How could you use the fraction tower to show the same thing? (e.g., I go to the 1 _

3 row to show both fractions. 2 _

3 is two 1 _ 3 s and that goes farther to the right than 1 _

3 does)

Using the Open QuestionProvide the Fraction Tower (1) template for students to use, if needed.

By viewing or listening to student responses, note if they require the support of the visuals or recognize that if fractions have the same denominator, the fraction with the greater numerator is the greater fraction.

Dependingonstudentresponses,useyourprofessionaljudgementtoguidespecificfollow-up.

Consolidating and Reflecting on the Open Question◊Whattwofractionsdidyoucomparefirst?(e.g., 3 _

8 and 5 _ 8 )

◊How did you decide which was greater? (e.g., I knew 5 _ 8 was greater since it was

more eighths.)◊Would it be easy to compare 3 _

20 to 4 _ 20 without a picture? How? (e.g., yes, 4 _

20 is more since there are more twentieths)

solutionsSample responses

2 _ 3 and 1 _

3 are not the same size since 2 _ 3 is two sets of 1 _

3 , so that’s more. It makes sense since two of anything is more than one of that thing.

3 _ 8 and 5 _

8 are not the same size since 3 _ 8 is 3 sections that are each 1 _

8 long, but 5 _ 8 is 5 of

those sections and 5 is more than 3. I don’t need a picture to see that.

4 _ 10 and 11

_

10 are not the same size since 4 _ 10 is less than a whole and 11

_

10 is more than a whole and 10

_

10 is a whole. Something more than a whole is greater than something less than a whole.

Materials• FractionTower(1)template

• patternblocks

8 © Marian Small, 2010 Comparing Fractions

Comparing Fractions with the same Denominator

open Question

2–3

1–3

3–8

5–8

9–8

4––10

11––10

9––10

Choose two fractions with the same denominator.

How do you know that the two fractions are not the same size?

How could you decide which is greater without using a picture?

Show your work in the box.

Repeat with two other pairs of fractions.

Comparing Fractions © Marian Small, 2010 23

Fraction Tower (1)

1 _ 101 _ 10

1 _ 101 _ 10

1 _ 10

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 31 _ 3

1 _ 3

1

1 _ 101 _ 10

1 _ 101 _ 10

1 _ 10

Page 13: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

12 © Marian Small, 2010 Comparing Fractions

think sheet

Questions to Ask Before Assigning the Think SheetStudents to use pattern blocks to show 1 _

3 and then 2 _ 3 . Ask:

◊How do your models show why 2 _ 3 > 1 _

3 ? (e.g.,Theycovermoreofthehexagon.)◊Didyoufindthatsurprising?(no, 2 of something is more than 1 of it)◊How could you use the fraction tower to show the same thing? (I go to the 1 _

3 row to show both fractions. 2 _

3 is two 1 _ 3 s and that goes farther to the right than 1 _

3 does)

Using the Think SheetReadtheshadedintroductoryboxwiththestudents.

Make sure they understand that the numerator tells how many sections and the denominator indirectly indicates the size of the section.

Assign the tasks.

Indicate that students are free to use the Fraction Tower (2) template, if needed.

By viewing or listening to student responses, note if they observe that when fractions have the same denominator, the fraction with the greater numerator is the greater fraction and why.

Depending on student responses, use your professional judgement to guide further follow-up.

Consolidating and Reflecting: Questions to Ask After Using the Think Sheet◊ Istheremorethanonewaytofigureout,forQuestion1b,whichfractionisgreater?

(e.g., Yes, since 8 _ 5 ismorefifthssothatmakesitgreater,butit’salsomorethan

1 and 3 _ 5 is less than 1, so that’s another reason it’s greater.)

◊For Question 3, how did you know that 1 could not be an answer for 3a? (e.g., I know that the number has to be more than 2.)

◊How did you start Question 4? Why did you start that way? (e.g., I knew that the missing number for the second one couldn’t be 0, 1, or 2. I know 0 of anything is small,soithadtobethelastnumeratororthefirstnumerator.)

◊What rule could you give for comparing fractions with the same denominator and why does it work? (e.g., The fraction with the greater numerator is greater since there are more pieces and all the pieces are the same for both fractions.)

solutions1. a) 3 _

5 b) 8 _ 5 c) 9 _

9 d) 4 _ 3

2. e.g., 5 _ 12 is 5 sections of 1 _

12 and 7 _ 12 is 7 sections of 1 _

12 sotherearetwoextrasections;that makes it more.

3. a) e.g., 3 and 4 b) e.g., 1 and 2 c) e.g., 3 and 5

4. e.g., 1 _ 5 < 2 _

5 3 _ 8 > 2 _

8 0 _ 5 < 4 _

5

Comparing Fractions © Marian Small, 2010 9

Comparing Fractions with the same Denominator (Continued)

think sheet

If two fractions have the same denominator, they are easy to compare.

For example,3–8 >

2–8

3–8 is 3 copies of

1–8

2–8 is 2 copies of

1–8

3 copies > 2 copies3–8 >

2–8

The same is true even if the fractions are greater than 1.12––5 >

9–5

12––5 is 12 copies of

1–5one

9–5 is 9 copies of

1–5

whole

12 copies > 9 copies12––5 >

9–5

1. Circle the greater fraction in each pair.

a)3–5

1–5 b)

3–5

8–5

c)2–9

9–9 d)

4–3

2–3

10 © Marian Small, 2010 Comparing Fractions

Comparing Fractions with the same Denominator (Continued)

2. How can you explain to your friend why 5––12 <

7––12?

3. Choose two different values for each box to make the statement true.

a)2–3 < ––

32–3 < ––

3

b)5–8 > ––

85–8 > ––

8

c) ––12 <

7––12

––12 <

7––12

4. Fill in the boxes. Use each of the numbers: 0, 1, 2, 3, 4, and 5.

––5 < ––

5

––8 >

2–8

––5 < ––

24 © Marian Small, 2010 Comparing Fractions

Fraction Tower (2)

1 _ 101 _ 10

1 _ 101 _ 10

1 _ 10

1 _ 91 _ 9

1 _ 91 _ 9

1 _ 91 _ 9

1 _ 91 _ 9

1 _ 9

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 51 _ 5

1 _ 51 _ 5

1 _ 5

1 _ 31 _ 3

1 _ 3

1

1 _ 121 _ 12

1 _ 121 _ 12

1 _ 121 _ 12

1 _ 121 _ 12

1 _ 121 _ 12

1 _ 121 _ 12

1 _ 101 _ 10

1 _ 101 _ 10

1 _ 10

Materials• FractionTower(2)template

• patternblocks

Page 14: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

13 © Marian Small, 2010 Comparing Fractions

Comparing Fractions with the same numeratorLearning Goal•reasoningabouthowtwofractionswiththesamenumeratorcanbecompared.

open Question

Questions to Ask Before Using the Open Question◊Which do you think is more: 3 _

3 or 3 _ 4 ? (e.g., 3 _

4 since 3 _ 3 is a whole and 3 _

4 is less)

Have the student look at the 1 _ 3 and the 1 _

8 on the tower. Ask:◊Which fraction is greater? Why? ( 1 _

3 since it is a bigger piece)◊Why is it bigger? (since the whole is only 3 sections instead of 8 so there is more in

each section)◊What about 2 _

3 and 2 _ 8 which is more? Why? ( 2 _

3 , if there are two bigger sections and two littler sections, the two bigger ones are worth more)

Using the Open QuestionStudents can use the Fraction Tower (3) template, if needed.

By viewing or listening to student responses, note if they:• require the support of the visuals• recognize that if fractions have the same numerator, the fraction with the greater

denominator is the lesser fraction

Dependingonstudentresponses,useyourprofessionaljudgementtoguidespecificfollow-up.

Consolidating and Reflecting on the Open Question◊Whattwofractionsdidyoucomparefirst?(e.g., 4 _

8 and 4 _ 10 )

◊How did you decide which was greater? (e.g., I knew 4 _ 8 is 1 _

2 and 4 _ 10 is not even 1 _

2 since 1 _

2 is 5 _ 10 )

◊Howcouldyouusethesectionsizestohelpfigureoutthat4 _ 8 is more than 4 _

10 ? (e.g., I know that eighths are bigger than tenths and so 4 eighths is more than 4 tenths.)

◊Whyisitdifficulttotell,withoutapicture,whether3 _ 5 or 4 _

6 is greater, but easier to tell if 3 _

5 or 3 _ 6 is greater? (e.g.,IknowfifthsarebiggerthansixthssoifIhavethesame

number of each, I know 3 _ 5 ismore.Buteventhoughsixthsaresmaller,ifIhave

moreofthem(likewith4sixthscomparedto3fifths),Idon’tknowwhichismoreintotal.)

◊How could you advise someone to compare two fractions like 4 _ and 4 _

if you don’t know exactly what the denominators are? (e.g., I would tell them that whichever is the bigger denominator is the smaller fraction since the pieces are bigger and 4 big pieces is always more than 4 little ones.)

solutionsSample responses:

4 _ 8 and 4 _

10 are not the same size since if the whole is divided into 10, the pieces are smaller than when it is divided into 8. So I am comparing 4 smaller pieces to 4 bigger ones. That means that 4 _

8 > 4 _ 10 . I don’t need a picture to tell.

5 _ 2 > 5 _

8 since 5 _ 2 is more than one whole (which is only 2 _

2 ) and 5 _ 8 is less than a whole,

since it’s not 8 _ 8

6 _ 9 < 6 _

8 sinceninthsaresmallerthaneighthssosixsmallpiecesarelessthansixbigger ones

Materials•Fraction Tower(3)template

Comparing Fractions © Marian Small, 2010 11

Comparing Fractions with the same numerator

open Question

4–8

4––10

4–3

5–8

5–2

5––10

6–9

6–8

6–4

Choose two fractions from the list with the same numerator.

How do you know that the two fractions are not the same size?

How could you decide which is greater without using a picture?

Show your work in the boxes.

Repeat with two other pairs of fractions.

Comparing Fractions © Marian Small, 2010 25

Fraction Tower (3)

1 _ 101 _ 10

1 _ 101 _ 10

1 _ 10

1 _ 91 _ 9

1 _ 91 _ 9

1 _ 91 _ 9

1 _ 91 _ 9

1 _ 9

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 81 _ 8

1 _ 41 _ 4

1 _ 41 _ 4

1 _ 31 _ 3

1 _ 3

1 _ 21 _ 2

1

1 _ 101 _ 10

1 _ 101 _ 10

1 _ 10

Page 15: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

14 © Marian Small, 2010 Comparing Fractions

think sheet

Questions to Ask Before Assigning the Think Sheet◊Which do you think is more 3 _

3 or 3 _ 4 ? (e.g., 3 _

4 since 3 _ 3 is a whole and 3 _

4 is less)

Have the student look at the 1 _ 3 and the 1 _

8 on the tower. Ask:◊Which fraction is greater? Why? (e.g., 1 _

3 since it is a bigger piece)◊Why is it bigger? (e.g., since the whole is only 3 sections instead of 8 so there is

more in each section)◊Which is more 2 _

3 or 2 _ 8 ? Why? ( 2 _

3 , e.g., if there are two bigger sections and two littler sections, the two bigger ones are worth more)

Using the Think SheetReadtheshadedintroductoryboxwiththestudents.

Make sure they understand that the numerator tells how many sections and the denominator indirectly indicates the size of the section.

Assign the tasks.

Indicate that students can use the Fraction Tower (4) template.

By viewing or listening to student responses, note if they observe that when fractions have the same numerator, the fraction with the greater denominator is the lesser fraction and why.

Depending on student responses, use your professional judgement to guide further follow-up.

Consolidating and Reflecting: Questions to Ask After Using the Think Sheet◊ Istheremorethanonewaytofigureout,forQuestion1c,whichfractionisgreater?

(e.g., yes, since 2 _ 9 is way less than half and 2 _

3 is more, I know 2 _ 3 is bigger but I also

know that 2 thirds is more since thirds are bigger than ninths, so 2 _ 3 > 2 _

9 )◊For Question 3, how did you know that 1 could not be an answer for 3a?

(e.g., I know that the number has to be more than 3.)◊How did you start Question 4? (e.g., I know it’s easiest to compare if the denominatorsornumeratorsarethesame,soIused4forthefirstfractionand3forthe second one.)

solutions1. a) 3 _

8 b) 4 _ 5 c) 2 _

3 d) 5 _ 2

2. e.g., If something is divided into 12 pieces, each piece is smaller since there are more pieces. That means twelfths are smaller than eighths, so 5 _

12 is less than 5 _ 8 .

3. a) e.g., 4 and 5 b) e.g., 9 and 10 c) e.g., 3 and 4

4. 4 _ 10 > 4 _

12 3 _ 5 > 3 _

8 1 _ 2 > 1 _

5 3 _ 1 > 3 _

2

12 © Marian Small, 2010 Comparing Fractions

Comparing Fractions with the same numerator (Continued)

think sheet

If two fractions have the same numerator, they are easy to compare.

For example,3–8 <

3–5

3–8 is 3 copies of

1–8

3–5 is 3 copies of

1–5

1–8 <

1–5 since the whole is shared into more pieces,

which means the pieces are smaller.

3–8 <

3–5

The same is true if the fractions are greater than 1.8–5 <

8–3

8–3 is 8 copies of

1–3

8–5 is 8 copies of

1–5

1–5 <

1–3

8–5 <

8–3

1. Circle the greater fraction in each pair.

a)3–8

3––10 b)

4––12

4–5

c)2–9

2–3 d)

5–3

5–2

Comparing Fractions © Marian Small, 2010 13

Comparing Fractions with the same numerator (Continued)

2. How can you explain to your friend why 5––12 <

5–8? It doesn’t make sense

to her since 12 > 8. What could you say to help?

3. Choose two different values for each part to make the statement true.

a)2–3 >

2–– 2–3 >

2––

b)5–8 >

5––

5–8 >

5––

c)3

–– >3–5

3–– >

3–5

4. Fill in the boxes. Use each of the numbers 1, 2, 3, 4, and 5.

4––10 > ––

12

3–5 > ––

8

1–2 >

1––

3–– >

3––

26 © Marian Small, 2010 Comparing Fractions

Fraction Tower (4)

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_10

1_10

1_10

1_10

1_10

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_6

1_6

1_6

1_6

1_6

1_6

1_5

1_5

1_5

1_5

1_5

1_4

1_4

1_4

1_4

1_3

1_3

1_3

1_2

1_2

1

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_10

1_10

1_10

1_10

1_10

Materials• FractionTower(4)template

Page 16: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

15 © Marian Small, 2010 Comparing Fractions

Equivalent FractionsLearning Goal•representingthesamefractionindifferentways.

open Question

Questions to Ask Before Using the Open Question◊Suppose a pie was cut into 8 equal pieces. How many pieces would be half of it?

Why? (4 pieces since there would be two equal shares of 4)◊How does that tell you that 1 _

2 = 4 _ 8 ? ( 4 _

8 is 4 pieces if there are 8 pieces in the pie and it’s half the pie)

◊We call fractions that are equal equivalent fractions. Can you think of another fraction equivalent to 1 _

2 ? (e.g., 5 _ 10 )

Help the student see why 1 _ 2 = 2 _

4 on the tower by showing how a vertical line down the right edge of 1 _

2 passes through the right edge of 2 _ 4 .

Using the open QuestionEncourage students to list as many possible equivalent fractions as they can, using the Fraction Tower (4) template.

Encourage them to look at the values of the equivalent fractions to see what they notice.

Dependingonstudentresponses,useyourprofessionaljudgementtoguidespecificfollow-up.

Consolidating and Reflecting on the Open Question◊Whichfractiondidyoufindthemostequivalentfractionsfor?Whydoyouthinkthat

happened? (e.g., 1 had the most equivalent fractions since each line was another name for 1)

◊Once you knew that 1 _ 3 = 2 _

6 , how did that help you predict other equivalent fractions? (e.g., I just doubled the numerators to get 2 _

3 = 4 _ 6 and then I also doubled the

numerator and denominator of 2 _ 6 to get 4 _

12 .)◊Look at all the equivalent fractions for 1 _

3 . What do you notice about the relationship between the numerator and denominator? (The denominator is always 3 times the numerator.)

◊How could that help you get more equivalent fractions? (e.g., I would just write any numerator I wanted and multiply by 3 to get the denominator.)

◊What rule could you give someone for getting equivalent fractions? (e.g., multiply the numerator and denominator by the same thing.)

Materials• FractionTower(4)template

• ruler(oranyobjectwithstraightedge)

26 © Marian Small, 2010 Comparing Fractions

Fraction Tower (4)

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_10

1_10

1_10

1_10

1_10

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_6

1_6

1_6

1_6

1_6

1_6

1_5

1_5

1_5

1_5

1_5

1_4

1_4

1_4

1_4

1_3

1_3

1_3

1_2

1_2

1

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_10

1_10

1_10

1_10

1_10

14 © Marian Small, 2010 Comparing Fractions

Equivalent Fractions

open Question

Look at the Fraction Tower.

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_10

1_10

1_10

1_10

1_10

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_6

1_6

1_6

1_6

1_6

1_6

1_5

1_5

1_5

1_5

1_5

1_4

1_4

1_4

1_4

1_3

1_3

1_3

1_2

1_2

1

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_10

1_10

1_10

1_10

1_10

Two fractions are equivalent, or equal, if they take up the same amount of area. For

example, use a ruler at the end of the1–3 and

2–6 sections to see why

1–3 =

2–6.

Find as many sets of equivalent fractions on the Fraction Tower as you can.

What do you notice about the numerators and denominators of equivalent fractions?

Page 17: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

16 © Marian Small, 2010 Comparing Fractions

solutionsAny or all of:

1 = 2 _ 2 = 3 _

3 = 4 _ 4 = 5 _

5 = 6 _ 6 = 8 _

8 = 9 _ 9 = 10

_

10 = 12

_ 12 = 15

_

15 = 18

_ 18 = 20

_

20

1 _ 2 = 2 _

4 = 3 _ 6 = 4 _

8 = 5 _ 10 = 6 _

12 = 9 _ 18 = 10

_

20

1 _ 3 = 2 _

6 = 3 _ 9 = 4 _

12 = 5 _ 15 = 6 _

18

2 _ 3 = 4 _

6 = 6 _ 9 = 8 _

12 = 10

_ 15 = 12

_

18

1 _ 4 = 2 _

8 = 3 _ 12 = 5 _

20

3 _ 4 = 6 _

8 = 9 _ 12 = 15

_

20

1 _ 5 = 2 _

10 = 3 _ 15 = 4 _

20

2 _ 5 = 4 _

10 = 6 _ 15 = 8 _

20

3 _ 5 = 6 _

10 = 9 _ 15 = 12

_

20

4 _ 5 = 8 _

10 = 12

_ 15 = 16

_

20

1 _ 6 = 2 _

12 = 3 _ 18

5 _ 6 = 10

_

12 = 15

_ 18

1 _ 9 = 2 _

18

4 _ 9 = 8 _

18

5 _ 9 = 10

_

18

7 _ 9 = 14

_

18

8 _ 9 = 16

_

18

1 _ 10 = 2 _

20

3 _ 10 = 6 _

20

7 _ 10 = 14

_

20

9 _ 10 = 18

_

20

I notice that every time you need to multiply the numerator and denominator of one fraction by the same amount to get the other fraction.

Page 18: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

17 © Marian Small, 2010 Comparing Fractions

think sheet

Questions to Ask Before Assigning the Think Sheet◊Suppose a pie was cut into 8 equal pieces. How many pieces would be half of it?

Why? (4 pieces since there would be two equal shares of 4)◊How does that tell you that 1 _

2 = 4 _ 8 ? ( 4 _

8 is 4 pieces if there are 8 pieces in the pie and it’s half the pie)

◊We call fractions that are equal “equivalent fractions”. Can you think of another fraction equivalent to 1 _

2 ? (e.g., 5 out of 10)

Using the Think SheetReadtheshadedintroductoryboxwiththestudents.

Make sure they understand that an equivalent fraction either uses the same space or represents the same ratio, i.e., ____ out of every ____.

Assign the tasks.

By viewing or listening to student responses, note if students:• can identify equivalent fractions• can create equivalent fractions either by multiplying both terms or dividing both

terms by the same amount• recognize patterns in equivalent fractions• recognize the difference in the effect of adding the same amount to both terms of a

fraction as compared to multiplying both terms by the same amount

Depending on student responses, use your professional judgement to guide further follow-up.

Consolidating and Reflecting: Questions to Ask After Using the Think Sheet◊Why are 2 _

3 and 12

_ 18 equal? (e.g., divide each third into 6 equal sections and you

have 12

_ 18 )

◊Why are 3 _ 5 and 8 _

10 not equal even though 8 is 5 more than 3 and 10 is 5 more than 5? (e.g., 3 _

5 is just a little bit over half but 8 _ 10 is almost the whole thing)

◊List some equivalent fractions for 3 _ 4 . How far apart are the denominators? Why?

(e.g., 6 _ 8 ,

9

_ 12 ,

12

_ 16 -thedenominatorsare4apart-ifyousplitthefourthsintosmaller

pieces,youget4extrapieceseachtime)◊For the last question, how did you know that if is big, then is little? (e.g., if is

big, then the fraction 6 _ is little so you need a little numerator for 3.)

solutions1. a, c, d

2. a) e.g., 10

_ 24 ,

15

_ 36 ,

20

_ 48

b) e.g., I would draw 5 _ 12 and break up each twelfth into 2 equal parts. Then there

would be 24 equal parts and 10 parts would be shaded, so that’s 10

_ 24 .

3. yes e.g., The equivalent fractions come from multiplying 2 and 3 by the same amount.Whenyoumultiplyby3,thereisanextragroupof3foreachextraamountin the number, so there is always 3 or 6 or 9, …

4. e.g., I know that 5 _ 6 is 1 _

6 away from 1, but 3 _ 4 is 1 _

4 away and since 1 _ 6 is less, it has to be

closer to 1.

5. e.g., 6 _ 1 = 18

_

3 or 6 _ 2 = 9 _

3 or 6 _ 3 = 6 _

3 or 6 _ 6 = 3 _

3

Comparing Fractions © Marian Small, 2010 15

Equivalent Fractions (Continued)

think sheet

Two fractions are equivalent if one is another name for the same amount.

For example,2–3 =

4–6 The fractions are equivalent since:

We can split the sections of•2–3 equally and it is the same part of the

whole.

2 out of every 3 is the same as 4 out of every 6.

Notice that if we multiply both the numerator and denominator by •the same amount (but not 0), we get an equivalent fraction. If we have 2 times or 3 times or 4 times as many pieces, we will have 2 times or 3 times or 4 times as many pieces of the type we want.

For example,3–5 =

3 × 3–––5 × 3 =

9––15

We can either split all the fi fths into 3 equal pieces or we can make 3 rows of 3 out of 5.

1. Which of these pairs of fractions are equivalent?

a)2–3

12––18 b)

3–5

8––10

c)5–8

10––16 d)

3––10

12––40

26 © Marian Small, 2010 Comparing Fractions

Fraction Tower (4)

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_10

1_10

1_10

1_10

1_10

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_6

1_6

1_6

1_6

1_6

1_6

1_5

1_5

1_5

1_5

1_5

1_4

1_4

1_4

1_4

1_3

1_3

1_3

1_2

1_2

1

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_10

1_10

1_10

1_10

1_10

16 © Marian Small, 2010 Comparing Fractions

Equivalent Fractions (Continued)

2. a) Name three fractions equivalent to 5––12.

b) Choose one of your fractions. How would you convince someone

who wasn’t sure why it is equivalent to5––12?

3. Jane listed equivalent fractions for 2–3. She noticed that the denominators

were always at least 3 apart. Do you agree? Explain.

4. How do you know that you cannot add 2 to the numerator and

denominator of3–4 and end up with an equivalent fraction?

5.6

–– = ––3 What can the values of and be?

=

=

Materials• FractionTower(4)template

Page 19: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

18 © Marian Small, 2010 Comparing Fractions

Comparing Fractions to 1 _ 2 and 1

Learning Goal•reasoningabouthowtwofractionscanbecomparedusingbenchmarksof½and1.

open Question

Questions to Ask Before Using the Open QuestionExaminethefractiontowerwiththestudents.Ask:◊How many thirds do you need to be past 1 _

2 ? ( 2 _ 3 )

◊How many fourths? ( 3 _ 4 )

◊Howmanyfifths?( 3 _ 5 )

◊What do you notice? (e.g., There were two lines in a row that needed the same number of sections to get past 1 _

2 and then it changed.)◊What if you used sixths and sevenths? (It would be 4 both times.)◊How could you predict that 7 _

10 is more than 1 _ 2 but 4 _

10 is less? (e.g., I know that 1 _ 2 = 5 _

10 so I have to go higher than 5 in the numerator to be more than 1 _

2 .)

Using the Open QuestionStudents can use the Fraction Tower (4) template.

Encourage students to come up with several values for each numerator or denominator.

Dependingonstudentresponses,useyourprofessionaljudgementtoguidespecificfollow-up.

Consolidating and Reflecting on the Open Question◊Was it easier to create fractions greater than 1 or less than 1 _

2 to make up the numerator? (e.g., greater than 1 since I just could add 1 to the denominator)

◊How could you be sure your fraction was less than 1 _ 2 ? (If I took half of the

denominator and the numerator was lower, I would be right.)◊ Is it easier to create fractions greater than 1 if you are given the denominator or the

numerator? (e.g., denominator, since I just keep adding 1s to get more and more numberators, but if I get the numerator, I can subtract, but I don't have as many possiblities)

◊ Is 14

_ 20 more or less than 1 _

2 ? How do you know? (e.g., more since 10

_ 20 is 1 _

2 and 14

_ 20 is more

than 10

_ 20 )

solutionse.g., 1 _

8 2 _ 5 4 _

10 3 _ 10 5 _

30 8 _ 20

I had to make sure that the denominator was more than double the numerator.

e.g., 9 _ 8 6 _

5 11

_ 10 3 _

2 5 _ 4 8 _

3

I had to make sure that the numerator was more than the denominator.

Materials• FractionTower(4)template

Comparing Fractions © Marian Small, 2010 17

Comparing Fractions to 1_2 and to 1

open Question

Choose values for the missing parts of the fractions so that they are less

than1–2. Use the same number only once. Tell how you chose the values.

––8

––5

––10

3––

5––

8––

Now choose values so that the fractions are greater than 1. Tell how you chose the values.

––8

––5

––10

3––

5––

8––

26 © Marian Small, 2010 Comparing Fractions

Fraction Tower (4)

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_10

1_10

1_10

1_10

1_10

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_6

1_6

1_6

1_6

1_6

1_6

1_5

1_5

1_5

1_5

1_5

1_4

1_4

1_4

1_4

1_3

1_3

1_3

1_2

1_2

1

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_10

1_10

1_10

1_10

1_10

Page 20: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire

19 © Marian Small, 2010 Comparing Fractions

think sheet

Questions to Ask Before Assigning the Think SheetExaminethefractiontowerwiththestudents.Ask:◊How many thirds do you need to be past 1 _

2 ? ( 2 _ 3 )

◊How many fourths? ( 3 _ 4 )

◊Howmanyfifths?( 3 _ 5 )

◊What do you notice? (e.g., There were two lines in a row that needed the same number of sections to get past 1 _

2 and then it changed.)◊What if you used sixths and sevenths? (It would be 4 both times.)◊How could you predict that 7 _

10 is more than 1 _ 2 but 4 _

10 is less? (e.g., I know that 1 _ 2 = 5 _

10 so I have to go higher than 5 in the numerator to be more than 1 _

2 .)

Using the Think SheetReadtheshadedintroductoryboxwiththestudents.

Indicate that the students can use the Fraction Tower (4) template.

Assign the tasks.

By viewing or listening to student responses, note if they realize that:• to compare to 1, they simply compare numerator and denominator and a greater

numerator means greater than 1• to compare to 1 _

2 , they can either take half the denominator and compare to the numerator or double the numerator and compare to the denominator

Depending on student responses, use your professional judgement to guide further follow-up.

Consolidating and Reflecting: Questions to Ask After Using the Think Sheet◊How did you know that 4 _

10 < 1 _ 2 ? (I know that 5 _

10 = 1 _ 2 and 4 _

10 is less.)◊How did you know that 2 _

9 was less than 1 _ 2 ? (e.g., I know that half of 9 is about 4, so a

little more than 4 _ 9 = 1 _

2 ; 2

_ 9 is less.)

◊ Is it easy to decide if a fraction is greater than 1? (Yes, the numerator is more than the denominator.)

◊What rule could you give for deciding if a fraction is between 1 _ 2 and 1? (e.g., The

numerator has to be less than the denominator or it would not be less than 1. But if you take half of the denominator, the numerator must be more than that or it wouldn’t be more than 1 _

2 .)

solutions1. 3 _

8 , 4

_ 10 ,

2

_ 5 ,

2

_ 9

2. 7 _ 8 and 3 _

5

3. 0, 1, 2, 3, or 4 since half of 9 is 4 1 _ 2 , so 5 would be too much

4. e.g., Any number greater than 6 makes _

6 >1 so you could go to the millions or higher but only 0, 1, 2, 3, 4, and 5 work if the fraction is less than 1.

5. Sample responses: e.g., 1 _

2 < 4 _ 6 8 _

10 > 1 _ 2 4 _

2 > 1 6 _ 8 > 1 _

2

Materials• FractionTower(4)template

18 © Marian Small, 2010 Comparing Fractions

Comparing Fractions to 1_2 and to 1 (Continued)

think sheet

Comparing to 1–2

A fraction equals1–2 if the denominator is 2 times the numerator.

For example,3–6 =

1–2 since 6 = 2 × 3.

A fraction is more than1–2 if the numerator is more than half the denominator.

For example,5–6 >

1–2 since half of 6 is 3. So

3–6 =

1–2 and

5–6 >

3–6.

1_2

A fraction is less than1–2 if the numerator is less than half of the denominator.

4––12 <

1–2 since half of 12 is 6. So

1–2 =

6––12 and

4––12 <

6––12.

1_2

Comparing to 1

A fraction equals 1 if the numerator and denominator are equal.

For example,4–4,

5–5,

6–6.

A fraction is more than 1 if the numerator is greater than the denominator.

For example,6–5 > 1 since 1 =

5–5 and

6–5 >

5–5.

1

A fraction is less than 1 if the numerator is less than the denominator.

For example,4–5 < 1 since it is only 4 out of 5 parts, not the whole

5–5.

1. Circle the fractions that are less than 1–2.

3–8

4––10

2–5

2–9

2–3

2. Circle the fractions that are between 1–2 and 1.

7–8

6–4

2––10

3–5

5–3

Comparing Fractions © Marian Small, 2010 19

Comparing Fractions to 1_2 and to 1 (Continued)

3. What possible values could the numerator have if ––9 <

1–2? Why would

the numerator have just these values?

4. Replace the missing values with counting numbers (1, 2, 3,…).

Why are there more solutions to ––6 > 1 than to ––

6 < 1?

5. Fill in the boxes with 2, 4, 6, 8, 10. Use each number once to make these statements true.

1–2 <

4––8

–– >1–– ––

2 > 1 6

–– >1–2

26 © Marian Small, 2010 Comparing Fractions

Fraction Tower (4)

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_20

1_10

1_10

1_10

1_10

1_10

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_9

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_8

1_6

1_6

1_6

1_6

1_6

1_6

1_5

1_5

1_5

1_5

1_5

1_4

1_4

1_4

1_4

1_3

1_3

1_3

1_2

1_2

1

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_18

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_12

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_15

1_10

1_10

1_10

1_10

1_10

Page 21: Gap ClosinG - EduGAINs · Gap ClosinG Comparing Fractions Junior / intermediate Facilitator's Guide. Module 2 Comparing Fractions ... (e.g., fraction circles, Cuisenaire