Scientific Notation

Question 1

3.74 x 10^-15

+ 6.43 x 10^-3

__________________

Answer 1

6.43 x 10^-3

(in addition or subtraction of scientific notation, a number at least 100 times smaller can be considered negligible)

Question 2

5.32 x 10^-4

x 1.12 x 10^-13

__________________

Answer 2

something greater than 5.3 x 10^-17

Question 3

2.76 x 10⁴

+ 6.91 x 10⁵

__________________

Answer 3

72 x 10⁴ or 7.2 x 10⁵

Question 4

rearrange:

(3.2 x 10⁴) (4.9 x 10^-8)

________________________

(2.8 x 10^-7)

Answer 4

3 x 5 10⁴ x 10^-8

______ x _________

3 10^-7

≈ something greater than 5 x 10³

Question 5

(3.1 x 10⁷)² =

Answer 5

something greater than 9 x 10¹⁴

Question 6

(√8.1 x 10^­5)

Answer 6

(√81 x 10^­4) = (√81) x (√10⁴) = 9 x 10²

• the first step in taking the sq.rt of a term in scientific notation is to make the exponent even
• then take the sq.rt of the mantissa and exponential term separately

Question 7

1.6 x 10^-19 x 15

36²

Answer 7

1.6 x 10^-19 x 15

———————— =

(3. 6 x 10)²
1. 6 x 15 10^-19

————– x ———– = 1.9 x 10^-21

13 10²