6th Grade Math Textbook, Fundamentals

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5-8

Multiply: ()()

()() Multiply.



5 • ( 1 )

8 • 4

 1

4

 5

8

 1

4

 5

8

5

32 Both signs are negative,

so the product is positive.

1 Multiply: ()()

()() Multiply.



( 4 )• 2

5 • 3

2

3

2

3

 4

5

 4

5

 8

15 The signs are unlike, so

the product is negative.

2

Update your skills. See page 414 XVII.

Multiply Fractions

Objective To multiply positive and negative fractions• To multiply positive and negative

fractions and integers• To evaluate algebraic expressions involving multiplication of fractions

Star Middle School has designed a new flag to represent its

sports teams. It is blue and white. It has stars on of the

blue section. What fraction of the whole flag has stars?

To find the part with stars, of , multiply •.

You can draw an area model to show multiplication of fractions.

Find of , or •.

Divide a rectangle into halves. Shade blue.

Divide the rectangle into fifths. Shade yellow.

Count the parts that are shaded both yellow and blue. 2 parts shaded both yellow and blue

Count the total number of parts. 10 parts in all

So of is , or.

So of the flag has stars.

To multiply positive and negative fractions, multiply numerators and

denominators. Use the same sign rules as for multiplying integers.

Multiply: ()

• 

 Simplify. Divide by the GCF.

 Simplest form

1

2

2

5

1

5

Multiply the numerators.

Multiply the denominators.

1

5

2  2

10  2

2

10

2 • 1

5 • 2

1

2

2

5

2

10

1

2

1

5

2

5

2

5

1

2

2

5

2

5

1

2

1

2

1

2

1

2

2

5

2

5

2

5

1

2

1

2

Key Concept

Multiply Fractions

()()ab dc bdac, where b0 and d^0