3 rd grade division

8/11/2019 3 Rd Grade Division

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Imagine you work at an

orchard and have 27 apples

Ok, but your apples are

Green

And theyre in a basket


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1

27


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Your boss at the orchard tells you to put the green ap

into bags that hold three apples each

If you had x-ray vision,this is what youd see in

this bag

I promise

= 1 2 3


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How would you figure out how many bags you would

need for the 27 apples?

6 bags is only enough for apples18

1 23

45 6


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One way to solve this problem would be to

take

3 apples out of the basket and put them inone bag.To start: 27 - 3 = 24 apples left in the basket

And one bag with 3 apples

1 2 3


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1

24


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You could repeat: take 3 more out of the

basket: 24 - 3 = 21apples left in thebasket

And you would have 2 bags

holding 6 apples in total1

2

1 2 3

4 5 6


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1

21


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Can you figure out howmany times you could

take 3 apples out of the

basket before the basketis empty?

Whats your answer?


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1234

7 6 5

9

8

If you said 9 times,

youd be correct


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How can you show all this

mathematically?

9 X 3 =27

or

273

27or 3

Because 9 groups of 3= 27

The last two both mean27 divided by 3


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You have a giant container of ice cream and youre going to makquadruple scoop cones for your friends. The container has enou

ice cream for 28 scoops. How many quadruple-scoop cones can

A quadruple scoop cone has how manyscoops of

Ice-cream4

Work on this one!!!

By the way,


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Is this Mr. R. when he was a kid

1

2

3

4


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What does the question look like mathematically?

62 = 3 equal groups with 2 in each group

62

Division is sharing or grouping a number into equal parts

3

But lets get back to the ice cream

For example


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We have 28 scoops of ice cream and we

need to find out how many equal groups of 4

we can make. How can we write a mathsentence to represent this?

Is it 28 4Is it 4 x 28?

Is it 28 + 4

Is it 28 - 4

Is it 28 - 8?

Which one of these is used to share 28 into equal groups of 4


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Sometimes to solve a division problem like 28 4, we

we may use a lot of subtraction

28 - 4 = 24

24 - 4 = 20

20 - 4 = 16

1 cone

2 cones

3 cones

You can continue subtracting 4 scoops

of ice cream until there are none left


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Besides subtraction, we could draw a diagram o

use manipulatives for help


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Here we use a diagram to divide the

28 ice cream scoops into groups of 4


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If 4 cones = 16 scoops

How many cones would it take to reach 28 scoops?


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What number (of cones), multiplied by 4 (scoops of ice cream) =

28 scoops in all?

6 x 4 =

7 x 4 =

5 cones x 4 scoops = 20 scoops

24 scoops

28 scoops


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Finally, you can use fact families to help with division

If 7 x 4 = 28

Than 28 4 = 7


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Now its ice cream time!!!


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You have a container of ice cream and youre going to matriple scoop cones for your friends. The container holds

18 scoops. How many triple-scoop cones can you make?

A triple scoop cone has h scoops of ice-cream3

Work on this one!!!

By the way,


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Part 2


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What in the world would you do if you had 771 apples

in your basket???

We would need a bigger basket

First of all, you would

need a bigger basket


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Still not 771!!!!


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And still not at 771!!


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Anyway, your boss wants you to put 3 apples in each bag agai

wants you to keep track of how many bags you used.

Can you estimate how many bags

you would need for 771 apples?

= 1 2 3


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Do you think you would you need

more than 100 bags for the 771 apples?

Why?


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Im tired of apples, I want ice cream!!!

fourt

h


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I guess you could figure out how many bags

you would need by taking away 3 apples at a tim

771-3= 768-3= 765-3=762-3 -3=759 -3=756 -3= 753 -3= 750

But that would take a long time, wouldnt it?


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What if you took 300 apples out

of the basket all at once?

Can you figure out how many bags

you would need to hold 300 apples?


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If you said bags, youd be correct

Lets put those 300 apples in 100 REDbags.

100


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How many apples

would you haveleft in your

basket?


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Well, 771-300 =

471Apples left


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Uh-oh, you have 100redbags of apples, (with 300 apples in

But you still have 471apples left in your basket

I think you NEED more bags!!


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Hey, maybe you can fill

another 100bags?

What do you think?

Why?


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Sure you can, because you have more

Applesapples left.300


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So you tell your boss you have apples le

and you need 100 more bags to holdmore apples.

471

300


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This time, you put the 300 apples in BLUEbags


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Now you have 200 bags that are holding

RED bags

and

BLUE bags

apples600

100

100


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How many apples would you have left in your bask

More than whats in

this basket!!!


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If you thought:

471 apples minus 300 apple

youd be correct

171Thats equal to ap


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No, you cant eat them- 171 apples will

upset your stomach, besides, you have to

sell them so you can buy your teachers big birgifts

Can you fill another 100 bags with apple

Why?

What will you do with those 171 apples

that are still in the basket?


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Just how many bags can you fill with your 171 a


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Can you think of any multiple of 3 th

less than 171? Lets try some

3 x 90 bags =

Thats more than 171 apples

3 x 80 bags=

Nope, still too much

270 apples

240 apples


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How can you figure out a multiple that is less

than 171

Yup, its a great time to use those

mental math multiplication skills!!!


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3 x 50 =

Thats less than 171

You can take apples

out of the basket.

150

150

How about 3 x 50


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Lets make 50more bags of 3 apples ea

Well use greenbags this time!!


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Okay, lets review

You took out 300 apples,

and put them in 100 redbags


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Then you took out 300 more apples,

And put those in 100 bluebags


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Then you took 150 apples from the bask

and put those in 50greenbags

How many bags have we used together

100 red + 100 blue + 50 green


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bags in all !!!

250


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But you still have apples in our bask

What are you ever going to do?

NO YOU CANT EAT THEM!!!


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First of all, how many apples are left

You had 171, and you took out 150.

Figure that out


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If you said,

you would be correct21 apples,


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Can you find a multiple of 3 thats

less than, or equal to 21???

Think multiplication tables


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10 x 3 = 30 apples

Too manyits more than 21 apples you

5 x 3 = 15 apples

You could use 5, because you do have 15 a

but is there a better choice?

What do you think?


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Sure, 7 x 3 = 21

Oh, so you thought of a multiple

will give you exactly 21 apples?


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So you need 7 more bags to hold the remaining

21 applesLets use purple bags


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Do you have any apples left in your basket?

I think you can tell your boss that youre done!!

No, not in this basket


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But your boss wants to know

how many bags you used altoget

Lets count our bags


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100 redbags

100 bluebags

50 greenbags

7 purplebags

bags altogether!!!257

et s cou t ou bags

Lets count our apples


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100 redbags

100 bluebags

50 greenbags

7 purplebags

= 257 bags in all

300 apples

300 apples

150 apples

21 apples

apples in all

pp

771


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So 771 divided into groups of 3 =

With a remainder of 0 apples!!!

257


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Now you can eat an apple!!!

BUT WAIT!!!!!!


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What does all of that look like as a division pro

771 3

or

7713

Lets do this on paper Please get a blank sheet out


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Let s do this on paper Please get a blank sheet out

Lets think about how you subtracted apples

7713

First we subtracted 300 apples from 771 using 100 redbag

100 bags

-300

471 left

Then we subtracted 300 more apples from the


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7713 7713

pp

remaining 471 using another 100 blue bags

100 bags

-300

471

-300

171 left

100 bags

Then we subtracted 150apples from the remaining 171


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7713 7713

pp g

using 50 greenbags

100 bags

-300

471

-300

171

100 bags

50 bags

-150

21 left

Then we subtracted 21 more 7 bags


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7713 7713

Then we subtracted 21more

apples using 7purplebags

100 bags

-300

471

-300

171

100 bags50 bags

-15021

g

-21

0 left

257


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6333

Add up the bags and thats 257bags!!!

Can you solve this one using the same met

3 rd grade division

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