Multiplying Positive and Negative Fractions

Warm-UpA recipe for cupcakes calls for 3 1/3 cups of

flour. How much flour would you need to make 4 batches of cupcakes?

Multiplying FractionsRecord in your Math Journal on page M:

To multiply fractions, multiply the numerators together, then multiply the denominators together, and reduce.

4 3

Para multiplicar fracciones, multiplique los numeradores juntos, y luego multiplicar los denominadores juntos, y reducir.

*9 5

4 3 12*9 5 = 45

Then reduce.

El reducir.

12 3 445 3 15

÷ =

+ Same - Different

Multiply Positive FractionsExample Problem

5/12 X 3/20

4/9 X 3/5

1/4 X 2/3

7/10 X 7/16

Multiply Negative FractionsExample Problem

-5/6 X 3/8

8/9 X -3/4

-3/5 X 7/9

(-1/2) X (-6/7)

Multiply Mixed NumbersExample Problem

4 1/2 X 2 2/3

1 1/2 X 1 2/3

5/7 X 1 3/5

(-2 1/6) X (-1 1/5)

A roller coaster at Six Flags is 160 feet high. If a new roller coaster is built that is 2 3/5

times the height of the existing coaster, what is the height of

the new roller coaster?

A piece of lumber is 4 ¼ feet long. If you need a piece of lumber that is 2/3 this size,

how long a piece do you need?

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Activity 1:

Multiplying Fractions Skills Practice