Math Unit 6 Multiplying Decimals Review

Vocabulary

100

To change the value of a number to one that is easier to work with. 

round

200

A number close to an exact value.

Estimate

300

The answer to a multiplication problem. 

Product

400

To divide or "break up."

partition

500

The answer when adding

sum

Powers of 10

100

6.5 x 10⁴ =

65,000

200

8.3 x 10² = 

830

300

6.7 x 10⁵ =

670,000

400

7.7 x 10³ =

7,700

500

1.2 x 10¹ = 

12

Estimate Products

100

Estimate:

51.2 x 4.2 = 

200 or 204

200

Estimate:

11.8 x 75.5 =

912 or 800

300

Estimate by finding the range:

4.93 x 7.88 =

between 28 and 40

400

Estimate by finding the range:

7.77 x 10.8 =

Between 70 and 88

500

Estimate by finding the range:

16.12 x 3.55 =

Between 48 and 68

Generalizations about X decimals

100

3.8 is _____ of 38?

1/10

200

0.45 is _____ of 45

1/100

300

45 x 17 = 765

45 x 1.7 = _____

76.5

400

96 x 55 = 5,280

9.6 x 5.5 = ____

52.80 or 52.8

500

1.9 x 42 = 79.8

1.9 x 4.2 = ____

7.98

Multiplying Decimals

100

0.9 x 0.4 = 

0.36

200

0.5 x 0.6 = 

0.30

300

6.7 x 2.3 =

15.41

400

7.5 x 9 =

67.5

500

$1.80 x 16 =

$28.80