G8

Copyright © Swun MathCopyright © Swun Math (^) Grade 8 Unit 3 Lesson 7 P TE

Answer Key

Extension Activity

Answers will vary. Sample responses:

Addition

1.4 × 106 + 8.3 × 106 = 9.7 × 106

2.3 × 106 + 4.5 × 106 = 6.8 × 106

Subtraction

8.7 × 106 ─ 2.3 × 106 = 6.4 × 106

9.8 × 106 ─ 6.7 × 106 = 3.1 × 106

Homework

1. (5.4 × 10^2 ) × (0.51 × 10^3 ) not in scientific notation
   (5.4 × 10^2 ) × (5.1 × 10^2 )
   (5.4 × 5.1) × (10^2 × 10^2 )
   27.54 × 10^4 not in scientific notation
   2.754 × 10^5
   2. (23.85 × 10^2 ) ÷ (5.3 × 10^1 ) not in scientific notation
   (2.385 × 10^3 ) ÷ (5.3 × 10^1 )
   ퟐퟐ.ퟑퟑퟑퟑퟑퟑ
   ퟑퟑ.ퟑퟑ

⋅

ퟏퟏퟏퟏퟑퟑ

ퟏퟏퟏퟏퟏퟏ

0.45 × 103-1

0.45 × 10^2 not in scientific notation

4.5 × 10^1

3. (0.42 × 10^4 ) + (4.5 × 10^3 ) not in scientific notation
   (4.2 × 10^3 ) + (4.5 × 10^3 )
   (4.2 + 4.5) × 10^3
   8.7 × 10^3

4. (2.6)^2 × (10^6 )^2

6.76 × 106 × 2

6.76 × 10^12

5. (6 × 10^4 ) – (15 × 10^3 ) not in scientific notation
   (6 × 10^4 ) – (1.5 × 10^4 )
   (6 – 1.5) × 10^4
   4.5 × 10^4
   6. (1.65 × 103 ) + (3.1 × 102 ) do not have the same
   exponent
   (1.65 × 10^1 × 10^2 ) + (3.1 × 10^2 )

(16.5 × 10^2 ) + (3.1 × 10^2 )

(16.5 + 3.1) × 10^2

19.6 × 10^2 not in scientific notation

1.96 × 10^3