4-1 to 4-4 Review

Topic 4 Test Review Part 1

Lessons 4-1 through 4-4 Review

4-1: Multiply Decimals by Powers of 10

• When multiplying by a WHOLE NUMBER power of 10, the decimal point moves to the RIGHT

• When multiplying by a DECIMAL power of 10, the decimal point moves to the LEFT

• Add zeroes in blank spaces after moving the decimal point

Examples: Multiplying Decimals by Powers of 10

3.45 x 10 = 34.5
3.45 x 100 = 345
3.45 x 1,000 = 3,450 

Examples: Multiplying Decimals by Powers of 10

3.45 x 0.1 = 0.345
3.45 x 0.01 = 0.0345
3.45 x 0.001 = 0.00345

Multiple Choice

Some large envelopes are 0.085 cm thick. How thick is a stack of 100 envelopes packed on top of each other?

• 0.85 cm

• 8.5 cm

• 85 cm

• 850 cm

Multiple Choice

Tell if the number 10³

will make each equation true:

0.79 x 10³ = 790

• Yes

• No

Multiple Choice

Tell if the number 10³

will make each equation true:

0.63 x 10³ = 630

• Yes

• No

Multiple Choice

Tell if the number 10³

will make each equation true:

0.023 x 10³ = 23

• Yes

• No

Multiple Choice

Tell if the number 10³

will make each equation true:

14.5 x 10³ = 1,450

• Yes

• No

Multiple Choice

What is the product of 0.702 x 10²?

• 7.02

• 7,020

• 70.2

• 0.702

Multiple Choice

What is the product of 702 x 

 $\frac{1}{100}$ ? 

• 7.02

• 7,020

• 70.2

• 0.702

Multiple Choice

What is the product of 7.02 x  $10^3$  ?

• 7.02

• 7,020

• 70.2

• 0.702

Multiple Choice

What is the product of 702 x  $\frac{1}{10^3}$  ?

• 7.02

• 7,020

• 70.2

• 0.702

Fill in the Blank

Kaitlyn is planning a trip to Canada. Her cell phone plan includes a roaming charge of $0.48 per minute for calls made from Canada.

On her first day in Canada, Kaitlyn calls her parents in Missouri and talks for 10 minutes. What is the cost of this call?

Fill in the Blank

Kaitlyn is planning a trip to Canada. Her cell phone plan includes a roaming charge of $0.48 per minute for calls made from Canada.

During her trip, Kaitlyn’s calls to the United States total 100 minutes. What will be the total cost for these calls?

Multiple Choice

Choose Yes or No to tell if the decimal 0.29 will make each equation true.

10³ x __ = 29

• Yes

• No

Multiple Choice

Choose Yes or No to tell if the decimal 0.29 will make each equation true.

10⁰ x __ = 0.29

• Yes

• No

Multiple Choice

Choose Yes or No to tell if the decimal 0.29 will make each equation true.

10² x __ = 290

• Yes

• No

Multiple Choice

Choose Yes or No to tell if the decimal 0.29 will make each equation true.

10⁴ x __ = 2,900

• Yes

• No

Fill in the Blank

One inch equals 2.54 centimeters. How many centimeters is 10 inches?

Fill in the Blank

The area of one floor tile is 92.16 square inches. What is the area of a kitchen floor covered with 10² floor tiles?

4-2: Estimate the Product of a Decimal & a Whole Number

• You can estimate the product of a decimal and a whole number by using compatible numbers and rounding. 

  
  

• Remember, when estimating you always want to choose numbers that are as close as possible to the original numbers, but are still easy to compute.

Fill in the Blank

Every school day, Dylan rides the school bus 4.79 miles round trip between home and school.

Estimate the total distance Dylan rode the school bus last month, when there were 21 school days. Write an equation to model your work.

Fill in the Blank

A small business plans to order carpet for 4 identical offices. The floor of each office is 7.2 feet long and 5.8 feet wide.

Round the length and width to the nearest whole number. Then estimate the total amount of carpet that is needed.

Fill in the Blank

Estimate the cost of 15 paddle balls, if each paddle ball is $0.89

4-3: Use Models to Multiply a Decimal and a Whole Number

• Shade in the same number of squares as the decimal number, as many times as the whole number

• Remember, 1 whole grid = 1

• One column or row = 0.1

• One square = 0.01

Multiple Choice

Which equation does the grid represent?

• 1.6 x 0.3

• 2.6 x 0.3

• 16 x 3

• 0.16 x 0.03

Multiple Choice

What is the product of 1.6 x 0.3? Use the grid to help.

• 0.48 square mile

• 4.8 square mile

• 48 square mile

• 480 square mile

4-4: Multiply a Decimal by a Whole Number

• The steps used in multiplying a decimal by a whole number are similar to the steps used in multiplying a whole number by a whole number.

• Remember to take out the decimal point and multiply as normal, then add the decimal point back in

• Remember that multiply by 0.5 is like saying "half of"!

Multiple Choice

Solve:

6 x 0.5

• 30

• 0.3

• 0.03

• 3

Multiple Choice

Solve:

0.6 x 0.5

• 30

• 0.3

• 0.03

• 3

Multiple Choice

Solve:

60 x 0.5

• 30

• 0.3

• 0.03

• 3

Multiple Choice

Solve:

0.06 x 0.5

• 30

• 0.3

• 0.03

• 3

Fill in the Blank

Nina hiked 4.35 kilometers. Her sister Angela hiked 3 times as far as Nina. How far did Angela hike? Use the bar diagram to help you.

Fill in the Blank

How much will 5 balloons cost if each balloon costs $2.99?

Fill in the Blank

Every school day, Dylan rides the school bus 4.79 miles round trip between home and school (21 days).

Find the actual total distance Dylan rode the bus last month.