Division Stories

Lesson 6.2.5 1

Equivalent Fractions• Find at least 3 equivalent

fractions for each fraction shown.

2

1. 2.

3. 4.

Which One Doesn’t Belong?

• Identify the fraction that is not equivalent to the other three.

3

1.

2.

3.Answer

Dividing Fractions• Solve the following division

equations.

4

3.

2.1.

4.

Answer

Application Problem

Dao has pounds of ground meat. He is making ¼ pound burgers. How many hamburgers can he make?

5

Application ProblemDao has pounds of ground meat. He is making ¼ pound burgers. How many hamburgers can he make?

6

4

1

Dao can make 4 + 4 + 1 = 9 hamburgers.

4

Words to KnowMeasurement Division – a division problem

in which the number of groups is unknown.Example:

7

Partitive Division – a division problem in which the group size is unknown.Example:

5 Steps for Creating Word Problems

1. Decide on an interpretation (measurement or partitive)

2. Draw a model

3. Find the answer

4. Choose a unit

5. Set up the situation

8

Fraction Models

Fraction Bar8/9 ÷ 2/9

Number Line 11/8 ÷ 3/4

Area Model3/5 ÷ 1/4

9

Discussion• When we know the original amount and the size or

measure of one part, we use measurement division to find the number of parts. You can tell when a question is asking for measurement division because it asks, “How many _____ are in _________?”

• Writing division stories has five steps that are to be done in order.

• Today we will only look at measurement division, and tomorrow we will go on to partitive division problems.

10

HOW MANY?

How many?

in

Decide on an interpretation Given: measurement model

2Draw a model1/2

1/8 1/8 1/8 1/8

1/2

1

3Find the answer

There are four 1/8 in 1/2. 11

HOW MANY?

How many?

in

4

5Set up a situation

Choose a unit

The divisor and dividend must be the same unit.

Write an interesting, realistic, short, and clear story problem.

Work with a partner to create your own story problem. You may use the same unit, but your situation must be unique. You could try another unit such as ounces, yards, or miles if you prefer.

12

HOW MANY?Work with a partner to create your own story problem.

You may use the same unit, but your situation must be unique.

You could try another unit such as ounces, yards, or miles if you prefer.

4 513

HOW MANY?1. Bonnie Baker has a total of 1/2 pound of

chocolate. She needs 1/8 pound of chocolate for each batch of brownies she bakes. How many batches of brownies can Bonnie bake with 1/2 pound of chocolate?

 2.Tina uses 1/8 oz. of cinnamon each time she

makes a batch of coffee cake topping. How many batches can she make if she has 1/2 oz. left in her spice jar?

3. Eugenia has 1/2 yard of ribbon. For each party decoration, she needs 1/8 yard. How many party decorations can she make?

4 5

14

HOW MANY?

How many?

in

Decide on an interpretation Given: measurement model

2Draw a model

1

3Find the answer

There are 1 1/2 halves in 3/4. 15

1. Tia has 3/4 oz. of coffee left in her coffee can. She needs 1/2 oz. to make a cup of coffee. How many cups of coffee can she make?

2. Tiffany uses 1/2 oz. of glycerin each time she makes a batch of soap bubble mixture. How many batches can she make if she has 3/4 oz. left in her glycerin bottle?

 3. Theresa has 3/4 yard of fabric. For each doll

skirt she makes, she needs 1/2 yard. Does she have enough fabric to make 2 doll skirts?

4 5HOW MANY?

16

MATH TALK• How did we extend our work

with division with fractions in this lesson?

• What were your biggest challenges when writing story problems involving division with fractions?

17

LESSON SUMMARY• The method of creating division stories has

five steps, to be followed in order:• Step 1: Decide on an interpretation

(measurement or partitive). Today we used only measurement division.

• Step 2: Draw a model.• Step 3: Find the answer.• Step 4: Choose a unit.• Step 5: Set up a situation. This means writing

a story problem that is interesting, realistic, short, and clear and that has all the information necessary to solve it. It may take you several attempts before you find a story that works well with the given dividend and divisor.

18

Write a story problem for the following measurement division: 3/4 ÷ 1/8 = 6.

EXIT TICKETHOW

MANY?

1/4 1/4 1/4

1

1/8 1/8 1/81/81/81/8

19

Partitive Division

Maria has lb. of trail mix. She needs to

share it equally among 6 friends.

34

How many “parts” of trail mix can be made?

How can you show giving equal amounts of trail mix to each person?

1 2 3 4 5 6

20

cups of flour

Molly used 9 cups of flour to bake bread. If this was 3/4 of the total amount of flour she started with, what was the original amount of flour?

Measurement Division

a) Create a model to represent what the question is asking.

b) Explain how you would determine the answer using the model.

9 ÷ 3 = 3

34

9 ÷Solve 3 x 4 = 12

9 12

21

Which One Doesn’t Belong?

• Identify the fraction that is not equivalent to the other three.

22

1.

2.

3.Next Slide

Dividing Fractions• Solve the following division

equations.

23

4 3

8 3.

2.1.

4.

Next Slide