NF.4 & NF.5 Multiplying Fractions

Multiply Fractions

5

Determine the product: 10 x 1/5

10/5 or 2

10

Determine the product: 6/9 x 3/4

18/36 or 9/18 or 1/2

15

3/4 of 24

72/4 or 18

20

Determine the product (in simplest form): 8/5 x 5/2

4

25

Determine the product: 1 and 1/3 x 15

60/3 or 20

Story Problems

5

In a class of 10 students, each student is given 1/5 of a king size candy bar. How many candy bars will be needed for the class?

2 whole candy bars

10

Ethan looks at a recipe that calls for 1/4 cup of flour. If he wants to make the recipe 6 times, how many cups of flour will he need?

6/4 or 1 and 2/4 or 1 and 1/2 cups

15

What is the area of a rectangle with a length of 2/6 feet and a width of 9/4 feet?

Area = 18/24 ft² or 3/4 ft²

20

Zac says the area of a square with a length and width of 5/8 would = 10/16. Is he correct? If no, what's the correct answer? If yes, why?

No, because 5/8 x 5/8 = 25/64. Zac added across the tops and bottoms, not multiplied.

25

Sophia is painting a square shaped canvas. The length of each side is 1 and 1/3 feet long. What is the area of the painting?

Area = 16/9 ft² or 1 and 7/9 ft²

Scaling Fractions

5

Which of the following fractions when multiplied by 4 would DECREASE 4?

A.) 3/2   B.) 7/9   C.) 10/10

B.) 7/9 because it's less than 1

10

Which of the following fractions when multiplied by 4 would INCREASE 4?

A.) 6/3   B.) 12/16   C.) 1,453/1,453

A.) 6/3 because it's greater than 1

15

Which of the following fractions when multiplied by 4 would KEEP 4 the same?

A.) 15/3   B.) 1/4   C.) a/a

C.) a/a because it's the same variable on the top and bottom, so if a = 2, it would be 2/2.

20

When you multiply a given fraction by a factor less than 1, the product will ______ (always, sometimes, or never) be less than the given fraction.

ALWAYS. Anything multiplied by a factor less than 1 will always decrease.

25

What would happen to 2 and 1/4 in the following expression (increase, decrease, or stay the same?):

2 and 1/4 x 3/4

Decrease

Mixed Bag

5

True or False: the product of 7/5 x 1/3 is greater than 1/3.

True because 7/5 is greater than 1.

10

What does the story problem "of" signal you to do to the numbers? Example: Mr. A ate 1/2 of his 4 pizzas.

Multiply

15

True or False: 4/7 is the same as saying 4 x 1/7

True 4 x 1/7 = 4/7

20

In the choices below, which would make the following expression true? 4/11 x ___ > 4/11

A.) 2/2   B.) 5/6   C.) 8/5

C.) 8/5 because 8/5 is greater than 1

25

In a tutoring session, 2/3 of the hour is spent reviewing math problems. Adabella attended 3/4 of the tutoring session. How much time did she spend there?

6/12 or 1/2 of an hour