G8

Copyright © Swun MathCopyright © Swun Math Grade 8 Unit 3 Lesson 5 C TE

Answer Key

Homework

1. (1.5 × 10^4 ) × (5 × 10^4 )
   (1.5 × 5) × (10^4 × 10^4 )
   7.5 × 104 + 4^

Answer: 7.5 × 10^8

2. (2.5 × 10^3 ) × (3.1 × 10^1 )

(2.5 × 3.1) × (10^3 × 10^1 )

7.75 × 103 + 1^

Answer: 7.75 × 10^4

3. (9.4 × 10-^1 ) ÷ (4.7 × 10-^2 )
   1
   2

9.4 10

4.7 10

−

−

×

×

1

2

9.4 10

4.7 10

−

× −

2.0 × 10-1 – (-2)

Answer: 2 × 10^1

4. (6.1 × 10^2 ) × (1.5 × 10-^2 )

(6.1 × 1.5) × (10^2 × 10-2)

9.15 × 102 + (-2)

Answer: 9.15 × 10^0

5. (5.6 × 10-^1 ) × (1 × 10^6 )

(5.6 × 1) × (10-1 × 10^6 )

5.6 × 10-1 + 6^

Answer: 5.6 × 10^5

6. (1.0 × 10-^3 ) ÷ (2.5 × 10^1 )

3

1

1.0 10

2.5 10

× −

×

3

1

1.0 10

2.5 10

−

×^

0.4 × 10-3 – 1

0.4 × 10-4  Not in scientific notation

Answer: 4 × 10-5