Ch.6 Review

Estimate

100

Best estimate of the expression. 

5 x $4.31 =

5 x $5 =$25 

200

Estimate.

$17.24 x 6 =

Sample Answer(s): 

$120 **

$200

300

Best Estimate. (using easy mental math)

A smoothie shop sells 389.7 ounces of juice each week.
About how many ounces of juice will they sell in 4 weeks?

400 x 4 =1,600 ounces 

400

Estimate. 

55.3 ÷ 9  

54 ÷ 9 =6

Multiply Decimals

100

Multiply. 

3.8 x 7 = 

3.8 x 7 =26.6

200

Multiply. 

4.62 x 0.5 =

4.62 x 0.5 =2.31 

300

Multiply. Round to the nearest cent. 

Jasmine is buying a notebook that costs $2.45.
The sales tax is found by multiplying the cost of the notebook by 0.08.
What is the sales tax on the notebook?

$2.45 x 0.08 =$0.196 which is about $0.20  

400

Multiply. 

6.48 × 1,000 =

6.48 x 1,000 =6,480 

Divide a Decimal By a Whole #

100

Divide 

84.6 ÷ 18 =

84.6 ÷ 18 = 4.7 

200

Divide. Round to the nearest tenth if necessary. 

138.5 ÷ 16 =

138.5 ÷ 16 =8.656 which is about 8.7

Divide by Powers of 10

100

Divide. 

6.38 ÷ 10 =

Divide. 

6.38 ÷ 10 = 0.638

200

Divide. 

45.7 ÷ 100 =

45.7 ÷ 100 = 0.457

300

Divide. 

38.6 ÷ 1000 =

38.6 ÷ 1000=0.0386 

Divide Two Decimals

100

Divide. 

8.64 ÷ 2.4 =

8.64 ÷ 2.4 = 3.6

200

Divide. 

3.375 ÷ 0.75 =

3.375 ÷ 0.75 = 4.5

300

Divide. 

12.48 ÷ 0.32 =

12.48 ÷ 0.32 = 39

400

Divide. 

Ava drove 297.6 miles to visit her cousin. Her car used 6.2 gallons of gas.
How many miles per gallon did Ava’s car get?

297.6 ÷ 6.2=48 miles per gallon