Core Focus on Decimals& Fractions

Dividing Fractions with Models

Lesson 5.3

Warm-Up1. 21 ÷ 3

2. 16 ÷ 4

3. How many groups of 8 fit into the number 24?

4. How many groups of 4 fit into the number 32?

7

4

3

8

Dividing Fractions with Models

Use models to divide fractions.

Lesson 5.3

Good to Know!

DividendThe number being divided.

DivisorThe number used to divide.

QuotientThe answer to a division problem.

3 33

1212 14 2 4

4

Dividend

QuotientDivisor

Example 1Maelynn needs to measure cup of milk, but only has a cup measuring cup. How many times will she need to fill it?

Write the problem.

How many -sized groups are in the number ?

Draw a picture that represents the dividend, .

Circle groups that are the size of the divisor, .

Count how many groups of the divisor There are 3 circled groups of in . fit in the dividend to find the quotient.

Maelynn will need to fill the measuring cup 3 times.

34

14

3 14 4

34

14

3414

34

14

14

Example 2Clint need to make a platform that is inch thick. He has boards that are each inch thick. How many boards does he need to make the platform?

Write the problem.

How many -sized groups are in the number ?

Rename one or both of the fractionsso they have common denominators.

Draw a picture that represents thedividend, or .

Circle groups that are the size of thedivisor, .

Clint will need two boards, each inch thick, to make a inch thick platform.

3 34 8

3 64 8

343

8

34

38

34

68

38

Count how many groups of the divisor fit in the dividend to

find the quotient.

There are 2 circled groups of in

or .34

38

68

34

38

Explore! What Fits?Step 1 Choose one expression from the yellow box. (This example uses .)

Step 2 If the two fractions in this expression have the same denominator, go to Step 3. If the two fractions have unlike denominators, find a common denominator.

Step 3 Draw a rectangle. Divide it into as many sections as the denominator of the dividend. If you renamed the dividend in Step 2, use the new fraction.

Step 4 Color in as many sections as thenumerator of the dividend.

Step 5 Circle sets of your divisor in yourdrawing.

1 12 8

1 42 8

Explore! What Fits?Step 6 Count how many sets of the divisor are circled in your drawing.

Step 7 Write your drawing as an equation with an answer.

Step 8 Use Steps 1–7 to find the quotient of at least four different expressions from the yellow box.

1 1 2 8

Quotient

Communication PromptWhat is the process for finding the answer to using models?

121

65

Exit Problems1. Draw a model to represent . Find the quotient.

2. Draw a model to represent . Find the quotient.

3. Write the equation that matches the model.

4. Write the equation that matches the model.

51

54

72

76

4

3

or1 1 2 12 22 4 4 4

8 2 49 9