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Copyright © Swun MathCopyright © Swun Math Grade 8 Unit 3 Lesson 8 T TE

Math Task

Unit 3 · Lesson 8: Scientific Notation

Directions: Use different methods to simplify the following expressions. Then rewrite answers

in a notation other than scientific notation.

1. (5.6 × 10^5 ) ÷ (2 × 10^6 ) ─ (1.4 × 10 –1)


2. (45 × 10^2 ) × (4.7 × 10^9 ) + (5.2 × 10²)


3. (356 × 10^2 ) × (9.8 × 10^2 ) ÷ (2.8 × 10^5 )


4. Solution:

• (5.6 × 10^5 ) ÷ (2 × 10^6 )


• 5 .6⋅ 10

5

2⋅ 10^6 =^

• 52.^6 ⋅^10

5

106

• 2.8⋅^10

5

106

• (2.8 × 105–6^ ) ─ (1.4 × 10–1)

Answer: 1.4 × 10–1

2. Solution:

• Simplify multiplication portion
  first.


• (45 × 10^2 ) × (4.7 × 10^9 )


• (45 × 4.7) × (10^2 × 10^9 )


• 211.5 × 102+9


• 211.5 × 10^11 ( not scientific
  notation)


• 2.115 × 10^13

Answer: 2.115 × 10^13

3. Solution:

• Simplify multiplication portion
  first.


• [(356 × 10^2 ) × (9.8 × 10^2 )] ÷ (2.8 ×
  105 )


• [(356 × 9.8) × (10^2 × 10^2 )] ÷ (2.8 ×
  105 )


• (3488.8 × 10^4 ) ÷ (2.8 × 10^5 )


• Needs to be rewritten in
  scientific notation


• (3.4888 × 10^7 ) ÷ (2.8 × 10^5 )


• 3 .4888 ⋅10

7

2 .8⋅ 10^5

• 3.^48882. 8 ⋅^10

7

105

• 1.246 × 107-5

Answer: 1. 246 × 10^2

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