fraction concepts spring 2014 © dmti (2014) | resource materials

© DMTI (2014) | RESOURCE MATERIALS

Fraction Concepts

SPRING 2014


Week 1PARTITIONING, ITERATING, AND COMPARING USING BAR MODELS


Day 1: Paper Folding and Bar ModelsMaterials needed: Everyone should have four different colored paper strips of the same size (either 3x12in. or 2x8in.)

1. Here is a bar model that shows 0 to 1.

2. Fold one paper strip into two equal parts. This makes 2 ( units). 3. On the first bar model draw a dotted line to show how you folded the paper strip into units. Now, label your

drawing as shown.


Day 1: Paper Folding and Bar Models (cont.)• Think about the fraction . A fraction is a special kind of number that describes the

space between whole numbers (e.g. 0 to 1, 1 to 2).• The way we write a fraction is very important as each part tells us something about

the number.• The bottom part of a fraction is called the denominator and the top part of a fraction

is called the numerator. To understand fractions it is often best to look at the denominator (bottom part) first. Here is what the different parts of a fraction mean:

• Based on these descriptions, discuss with a partner what the fraction means. Use as many of the words above.

• Now use the words above to describe ? What about ?

Units counted Units to make 1 (unit size)

NumeratorDenominator

How many of the units I am counting in do I have? How many units (pieces) will it take to make 1.


Day 1: Partner Activity Example Statements

Discuss with a partner

Based on these descriptions, what does the fraction mean?

What about ?

What about ?

Example Descriptions

“It takes 2 ( units) to make 1 and you have counted only 1 of these units.”

“It takes 2 ( units) to make 1 and you have counted 2 of these units. That means is the same as 1.”

“It takes 2 ( units) to make 1 and you have counted 3 of these units. That means is more than 1.”


Day 1: Paper Folding and Bar Models (cont.)1. Fold another (second) paper strip into four equal parts. This will make 4 ( units). 2. Use dotted lines on the next bar model to show how you folded this new paper strip into fourths.3. Label the parts of the bar model.4. Now, your bar model for fourths should look like the one shown.

5. Use what you know about denominators and numerators to describe your bar model for fourths to a partner.


Day 1: Partner Activity Example Statements

Discuss with a partner

What does the fraction mean?

What about ?

What about ?

Example Descriptions

“It takes 4 ( units) to make 1 and you have counted only 1 of these units.”

“It takes 4 ( units) to make 1 and you have counted 3 of these units.”

“It takes 5 ( units) to make 1 and you have counted 5 of these units. That means is more than 1.”


Day 1: Paper Folding and Bar Models (cont.)1. Fold a new (third) paper strip into eight equal parts. This will make 8 ( units).2. Partition (split) a bar model into eighths in the same way you modeled halves and

fourths.3. Label the parts of the bar model.4. Now your bar model should look the one shown.


Day 1: Paper Folding and Bar Models (cont.)

Using your bar model drawings and folded paper strips, answer the following questions:

1. Which unit fraction is larger than ?

2. How many different ways can you make fractions that are the same size as ?

3. How many units will be the same as 3 ( units)?


Day 2:Bar Models7. Draw a bar model and label it 0 to 1 as shown*.

a. Partition the bar model into 3 equal parts. This will make thirds and show 3 ( units). Label each unit and show where , , and .

Make sure your bar model looks like this:

*If necessary, students can use paper strips and fold them into thirds prior to drawing their bar models


Day 2: Bar ModelsUsing your bar model for thirds to explain your answers, discuss the following questions with a partner:

b. How many units make 1?“It takes 3 units to make 1. That means 3 ( units) = 1.” c. What is the name for the size of each unit fraction?“Each unit fraction in the bar model is a unit. These are called thirds.” d. If we shaded one unit fraction, what would be the number name of the shaded part? “We would have shaded 1 ( unit) which is the number .” e. What would be the number name if we shaded two unit fractions?“We would have shaded 2 ( units) which is the number .”


Day 2: Bar Models8. Draw these two bar models to represent the number 1.


Day 2: Bar Modelsa. Partition one bar model into 3 ( units).


Day 2: Bar Modelsb. Partition the second bar model into 6 ( units). To do this, think about how many units

make 1 (which is the unit size) as well as how thirds might be related to sixths.


Day 2: Bar Modelsc. Using your bar models, discuss all of the relationships you can see between thirds and sixths with a

partner. (Write some of them down.)Examples: Which unit fraction is larger? What are some fractions that are the same if you made them with thirds and sixths? How many sixths are the same as ? How much of would cover?


Day 2: Bar Models

9. Draw five different bar models that represent 1.a. Use each bar model to shade and .

10. Compare the different sizes of each unit fraction.a. Which unit fraction is the largest?b. Which unit fraction is the smallest?c. Why?d. Order the unit fractions from least to greatest.


Day 3: Making 1Materials needed: Blank paper (turned to a landscape orientation and a single cube for each student.)

1. Place the cube on the left side of your paper and trace around it to make a unit. Then, remove the cube.

a. Label the unit as as shown below and be sure to show where 0 is, too.

b. If this unit is the unit fraction where would 1 be? Place a mark where you think 1 is. Then use the cube to iterate units until you get to 1. Was your prediction correct?

0


Day 3: Making 1 (cont.)

0

2. Use the cube to draw this unit on your paper and label it as shown.

a. If this unit is the unit fraction , mark where you think the following numbers are:

1

b. Now, use the cube to find whether your predictions were correct or not. Make sure to iterate the cube as a unit of and to label your model correctly.


Day 3: Making 1 If the cube is the unit fraction…. Find where these numbers are…

1

1

1

1

Now you will practice using the cube as different unit fractions and then find many numbers. Build models using the cube and label it for the following sets.


Day 4: Iterating Unit Fractions

Unit fraction

Number to make by iterating

Visual (bar model) Explanation

1 or “I iterated the unit fraction four times to make 1. That means 1 = 4

Follow the example below to create numbers by iterating the given unit fraction. Make sure you include a visual (bar model) and try to give an explanation that is similar to the example provided.


Day 4: Iterating Unit Fractions (cont.)

Unit fraction

Number to make by iterating

Visual (bar model) Explanation

1 or “I iterated the unit fraction four times to make 1. That means 1 = 4


Day 5: Comparing FractionsFor the following pairs of numbers, use bar models to show which is larger. Describe how you know your bar models are accurate and your answer is correct by using as many words as you can from the word bank. An example is provided.

Example: Which number is larger?

or

WORD BANK

denominator numerator unit fraction countunit size partition (partitioned) iterate (iterated)

“I first partitioned one bar model into thirds and the other into halves. Then, I iterated 2 ( units) and found that is larger than one unit.”


Day 5: Comparing FractionsFor the following pairs of numbers, use bar models to show which is larger. Describe how you know your bar models are accurate and your answer is correct by using as many words as you can from the word bank.

Which number is larger?

WORD BANK

denominator numerator unit fraction countunit size partition (partitioned) iterate (iterated)

a. or b. or c. or d. or e. or

f. or g. or h. or i. or j. or


Week 2NUMBER LINES, COMPOSING AND DECOMPOSING AND INTRODUCING ADDITION AND SUBTRACTION


Day 6: Number Lines

0 1

1. Draw the segment as shown below. Label it to make it a number line from 0 to 1.

a. Partition the number line into two equal parts.

b. What is the name for the units you made?

c. How many of these units make 1?


Day 6: Number Lines

0 1



b. What is the name for the units you made? unit fractions

c. How many of these units make 1?

unit unit


Day 6: Number Lines

0 1



b. What is the name for the units you made? unit fractions

c. How many of these units make 1? It takes 2( units) to make 1 so

unit unit


Day 6: Number Lines (cont.)0 1

2. Draw a new number line from 0 to 1 and label as shown above.


Day 6: Number Lines (cont.)

0 1

a. Partition the number line into 2( units) and label it as shown.



0 1

b. Use your number line to show 4( units)=1.c. How many fourths are equivalent to ? d. What are some other relationships between fourths and halves?



0 1

b. Use your number line to show 4( units)=1. c. How many fourths are equivalent to ? 2( units) = d. What are some other relationships between fourths and halves?

( unit)

04

24

44



0 1

e. Use what you know about fractions to model eighths on your number line. Label your number line accurately and discuss all of the relationships you see between halves, fourths and eighths with a partner.

04

24

44



0 1

e. Use what you know about fractions to model eighths on your number line. Label your number line accurately and discuss all of the relationships you see between halves, fourths and eighths with a partner.

04

24

44

28

48

68

88

08



3. Draw a new number line from 0 to 1.

a. Partition the number line into thirds.b. Mark the location c. Use what you know about denominators, numerators and unit fractions to explain the fraction



“I know that is composed of 2( units).”“The denominator of thirds means it will take 3( units) to make 1.”“The numerator 2 in the fraction means that we have counted 2 units of .”

0 1



d. Partition your number line into sixths. To do so, think about how thirds are related to sixths as well as what the numerator and denominator tell you.

e. How many units are the same as (equivalent) to ?

=


Day 7: Number Lines and Unit Fractions

1. Draw this number line from 0 to 2. a. Partition the segment from 0 to 1 into fourths using the strategies you learned

yesterday.

0 1 2



1. Draw this number line from 0 to 2. a. Partition the segment from 0 to 1 into fourths using the strategies you learned

yesterday. b. Continue partitioning the segment from 1 to 2 into fourths.

0 1 2



c. Use the unit fraction to count from 0 to . It should take 5( units) to make .

0 1 2



c. Use the unit fraction to count from 0 to . It should take 5( units) to make .

0 1 2

+ + + + +


Day 7: Number Lines and Unit Fractions (cont.)

For each of the following numbers, draw a number line from 0 to 2 and show how to iterate unit fractions to create the given number.

a. b. c. d.

e. f. g. g.


Day 8: Number Lines and Tree Diagrams

1. Draw four number lines that are partitioned into eighths and that also shows all of the halves and fourths between 0 and 1. (see example).

2. Use these number lines to show how the number can be decomposed into different groupings shown in the tree diagrams.

a. b. c. d.


Day 8: Number Lines and Tree Diagrams(cont.)

a.


Day 8: Number Lines and Tree Diagrams (cont.)

b.



c.

3. Explain how the distance of in the model is correct?Because = 2( units), that means moving 2( units) on the number line is the same distance as moving one unit.



d.

4. Explain how the distance of in the model is correct?Because = 4( units), that means moving 4( units) on the number line is the same distance as moving one unit.


Day 9: Number Lines, Tree Diagrams and Equations

1. Draw four number lines that are partitioned into sixths and thirds. (see example)

2. Use these number lines to show how the number can be decomposed into different groupings shown in the tree diagrams.

3. Write an equation (number sentence) that matches each tree diagram and your number lines. For example, . For each equation, write the numbers as shown in the tree diagram and also as fractions in the same unit.

a. b. c. d.



a.



b.



c.



d.


Day 10: Examining Incorrect Answers

Each of the following problems includes answers from three different students; Mark, Sasha and Israel. For each problem, one student is correct. The other two have provided incorrect answers.

1. Use a model to determine which answer is correct.2. Think about why the two students with incorrect answers may have thought their answers were correct.

What was the cause of their wrong answer?

a.

b.

Mark: Sasha: Israel:

Mark: Sasha: 1 Israel:


Day 10: Examining Incorrect Answers

Each of the following problems includes answers from three different students; Mark, Sasha and Israel. For each problem, one student is correct and the other two have provided incorrect answers.

1. Use a model to determine which answer is correct.2. Think about why the two students with incorrect answers may have thought their answers were correct.

What was the cause of their wrong answer?

c.

d.



fraction concepts spring 2014 © dmti (2014) | resource materials

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