6th Grade Math Textbook, Fundamentals

 &KDSWHU

5-9

Multiply: 2• ( (^3) )
Estimate first:  2  2  3  4 2 • (4)  8
Then multiply: 2• ( (^3) ) • () Rename each as a fraction greater than 1.
 • () Simplify. Divide by the GCF.

 Divide to rename as a mixed number.
 8
Check:8 is close to the estimate of 8. The answer is reasonable.
Multiply the numerators.
Multiply the denominators.
 7
(^21)
 12
5
 6
2
5
2
5
42
5
6 • ( 7 )
5 • 1
 7
2
 12
5
1
2
2
5
1
2
2
5
1
2
2
(^15)
Multiply Mixed Numbers
Objective To estimate the product of mixed numbers • To multiply positive and negative mixed
numbers • To evaluate algebraic expressions involving multiplication of fractions and mixed numbers
A mile is approximately 1 kilometers. Eli jogs 2 miles
every afternoon. About how many kilometers does he jog?
To find the number of kilometers, multiply: 2 • 1

First estimate by rounding to the nearest integer.

2  2 1  2 2 • 2  4 estimated product

To multiply mixed numbers, rename each mixed

number as a fraction greater than 1.

2• 1 • Rename each as a fraction greater than 1.

 Simplify. Divide by the GCF.



 Divide to rename as a mixed-number equivalent.

 3

Check:3 is close to the estimate of 4. The answer is reasonable.

Eli jogs 3 kilometers.

To multiply positive and negative mixed numbers, apply the sign

rules for multiplying integers. To multiply a mixed number and

an integer or a fraction, rename the mixed number.

Multiply the numerators.

Multiply the denominators.

3

5

3

5

3

5

18

5

9 • 2

1 • 5

98

45

2

1

8

5

9

4

3

5

1

4

3

5

1

4

3

5

1

4

1

4

3

5

Remember:To rename a mixed

number as a fraction:

abc(a • cc)b, c 0