Multiply and Divide Decimals

Estimate

100

Estimate 19.75 X 6

Sample: 20 x 6 = 120

200

Estimate 9 X 21.3

Sample 9 X 20 = 180

300

Estimate 71.9 divide by 8

Sample 72 divided by 8 = 9

400

Estimate: The Smith family drinks 473.2 ounces of water each week. About how many ounces of water will they drink in 4 weeks?

Sample: 500 X 4 = 2,000 

500

Estimate: Cam spends $26.77 when buying 3 CDs. If each CD costs the same amount, about how much does each CD cost?

Sample: 30 divided by 3 = 10

Powers of 10

100

Multiply 1.65 X 100

165

200

Multiply 20.69 X 10

206.9

300

Divide 27.3 divided by 1,000

0.0273

400

Divide 84 divided by 10

8.4

500

0.65 divided by 100

0.0065

Multiply

100

1.9 X 8

15.2

200

0.76 X 5

3.8

300

5.23 X 0.6

3.138

400

0.22 X 0.81

0.1782

500

Sam is buying a pack of gum that cost $0.65. The sales tax is found by multiplying the cost of the gum by 0.07. What is the sales tax on the gum?

$0.05  OR 0.0455

Divide

100

12.4 divided by 4

3.1

200

$79.75 divided by 5

$15.95

300

241.5 divided by 14

17.25

400

1.204 divded by 0.35

3.44

500

0.5 divided by 0.04

12.5