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Do you UNDERSTAND?Do you know HOW?

Dividing Unit Fractions by Non-Zero Whole Numbers

Independent Practice

Guided Practice

How can you model dividing a unit fraction by a whole number?Half of a casserole is left over. Ann, Beth, and Chuck are sharing the leftovers equally. What fraction of the original casserole does each person get?Make a drawing to show 1 __ 2 .

3. Construct Arguments In the example at the top, how is dividing by 3 the same as multiplying by 1 __

3 ?

4. Reasonableness When you divide a unit fraction by a whole number, will the quotient be greater than or less than the unit fraction?

Use the picture below to find each quotient.

1. 1 __ 4 4 2

2. 1 __ 4 4 4

Shade 1 __ 3 on a number line and divide 1 __ 3 into 4 equal parts.

Each part is 1 __ 12

.

Check with multiplication: 1 __ 12

3 4 5 4 __ 12

5 1 __ 3

Use a number line to find 1 __ 3 4 4.Other Examples:

Leveled Practice In 5–10, find the quotient.

5. 1 __ 2 4 5

6. 1 __ 5 4 2

7. 1 __ 2 4 3 8. 1 __ 4 4 3 9. 1 __ 3 4 4 10. 1 __ 4 4 5

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MATHEMATICAL PRACTICES

Common Core

5.NF.7.c Solve real world problems involving division of unit fractions by non-zero whole numbers and division of whole numbers by unit fractions, e.g., by using visual fraction models and equations to represent the problem. Also 5.NF.7

Lesson

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Divide 1 _ 2 into 3 equal parts.

1 __ 2 4 3

Each part contains 1 __ 6 of the whole.

So 1 __ 2 4 3 5 1 __ 6 .

Use multiplication to check.

3 3 1 __ 6 5 3 __ 6 5 1 __ 2

Each person gets 1 __ 6 of the casserole.

Problem Solving

11. Sue has 1 __ 2 gallon of milk. She needs to pour 4 glasses of milk.

What fraction of a gallon should she put in each glass?

12. Use Tools Who ran the farthest by the end of the week? Use the table below that shows the distances in miles.

13. Look for Patterns Write two decimals whose product is close to 9.8.

14. Reasonableness Without multiplying, order the following products from least to greatest.

2 3 3 __ 5 1 __ 4 3 3 __ 5 1 2 _ 5 3 3 __ 5 6 __ 6 3 3 __ 5

15. Find the area of the rectangle.

16. What division problem is modeled on the number line below? Find the quotient.

Monday Tuesday Wednesday Thursday Friday

Amir 2 1 __ 2  11 __2  31 __4  13 __4  21 __2 

Janie 23 __4  21 __2  33 __4  21 __4  11 __2 

MATHEMATICAL PRACTICES

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