Splash Screen. Lesson Menu Five-Minute Check (over Lesson 3–5) Main Idea Example 1:Multiply Decimals Example 2:Multiply Decimals Example 3:Annex Zeros.

Five-Minute Check (over Lesson 3–5)

Main Idea

Example 1:Multiply Decimals

Example 2:Multiply Decimals

Example 3:Annex Zeros in the Product

Example 4:Annex Zeros in the Product

Example 5:Multiply by 10, 100, or 1,000

• Estimate and find the product of decimals and whole numbers.

5

Multiply Decimals

Find 18.9 × 4.

Method 1 Use estimation.

Round 18.9 to 19.18.9 × 4 → 19 × 4 or 76

18.9× 4

3

Since the estimate is 76, place the decimal point after the 5.

6

3

.7

Multiply Decimals

Method 2 Count decimal places.

Answer: 75.6

one decimal place

Count one decimal place from the right.

5

18.9× 4

3

6

3

.7

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

A. 1.008

B. 10.08

C. 100.8

D. 1,008

Find 12.6 × 8.

Multiply Decimals

Find 0.56 × 7.

Method 1 Use estimation.

Round 0.56 to 0.5.0.56 × 7 → 0.5 × 7 or 3.5

Since the estimate is 3.5, place the decimal point after the 3.

9

0.56× 7

2

4

.3

Multiply Decimals

Answer: 3.92

Method 2 Count decimal places.

two decimal places

Count two decimal places from the right.

9

0.56× 7

2

4

.3

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

A. 0.332

B. 3.32

C. 33.2

D. 332

Find 0.83 × 4.

Annex Zeros in the Product

Find 3 × 0.016.

Answer: 0.048

three decimal places

Annex a zero on the left of 48 to make three decimal places.

48

1

0

0.016× 3 0.

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

A. 0.092

B. 0.92

C. 9.2

D. 92

Find 4 × 0.023.

ALGEBRA Evaluate 5g if g = 0.0091.

5g = 5 × 0.0091 Replace g with 0.0091.

Answer: 0.0455

Annex Zeros in the Product

four decimal places

Annex a zero to make four decimal places.

0.0455

0.0091× 5

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

A. 0.0186

B. 0.186

C. 1.86

D. 18.6

ALGEBRA Evaluate 3x if x = 0.0062.

MENTAL MATH Find 3.25 × 100.

Method 1 Use paper and pencil.

Multiply by 10, 100, or 1,000

Answer: 325.00

two decimal places

two decimal places

325.00

100× 3.25 500 2000 30000 +

Method 2 Use mental math.

Move the decimal point to the right the same number of zeros that are in 100, or 2 places.

Answer: 325

Multiply by 10, 100, or 1,000

3.25 × 100 = 3.25

1. A

2. B

3. C

4. D0% 0%0%0%

A. 24

B. 240

C. 2,400

D. 24,000

MENTAL MATH Find 2.4 × 1,000.

End of the Lesson

Five-Minute Check (over Lesson 3–5)

Image Bank

Math Tools

Modeling Decimals

Dividing Decimals

Modeling Decimals

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

Find 8.7 + 11.5.

A. 19.2

B. 20.1

C. 20.2

D. 21.2

(over Lesson 3-5)

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

Find 17.15 + 12.96.

A. 29.11

B. 29.95

C. 30.06

D. 30.11

(over Lesson 3-5)

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

Find 7.5 – 4.1.

A. 3.4

B. 3.6

C. 4.4

D. 5.6

(over Lesson 3-5)

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

Find 34.64 – 27.18.

A. 7.22

B. 7.46

C. 7.72

D. 8.56

(over Lesson 3-5)

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

Evaluate the expression a – b if a = 105.8 and b = 95.9.

A. 8.9

B. 9.7

C. 9.9

D. 10.3

(over Lesson 3-5)

1. A

2. B

3. C

4. D

0% 0%0%0%

Based on the information in the table, how much greater was Michael Young’s batting average than Jose Reyes’ batting average?

(over Lesson 3-5)

A. .058

B. .055

C. .041

D. .028