Question

Perform each of the following computations using the measured quantities below.

Answer 1

Question

Perform each of the following computations using the measured quantities below.

Write your final answer with the correct number of significant figures in proper scientific notation (one non-zero number to the left of the decimal point).

a. 917.2 + 45.63 = ___________

b. 3.423 x 10^-4 - 6.42 x 10^-3 =_________

Answer:

(a) 9.6 x 10²

(b) -6.1 x 10⁻³

Step-by-step explanation:

(a) 917.2 + 45.63

First add the two numbers as follows (ensure that the decimal numbers are well aligned);

   9  1   7 . 2

+     4  5 . 6  3

   9  6 2  . 8  3

To write the result in a proper scientific notation (one non-zero number to the left of the decimal point),

i. Express the number is standard form

962.83 = 9.6283 x 10²

Note that;

From the result in (i)

9.6283 = mantissa

10 = base

² = power or exponent.

ii. Express the mantissa of the number in 1 decimal place.

9.6 x 10²

Therefore, the result in the proper scientific notation is 9.6 x 10².

(b)  3.423 x 10⁻⁴ - 6.42 x 10⁻³

Find the difference between the two numbers as follows;

i. Re-write the numbers so that they both have the same exponents:

0.3423 x 10⁻³ - 6.42 x 10⁻³

ii. Factor out 10⁻³

10⁻³(0.3423 - 6.42)

iii. Solve the bracket

10⁻³(-6.0777)

iv. Rewrite the result in (iii)

-6.0777 x 10⁻³

To write the result in a proper scientific notation (one non-zero number to the left of the decimal point),

i. Express the number is standard form

-6.0777 x 10⁻³       [already in standard form]

Note that;

From the result in (i)

-6.0777 = mantissa

10 = base

⁻³ = power or exponent.

ii. Express the mantissa of the number in 1 decimal place.

-6.1 x 10⁻³

Therefore, the result in the proper scientific notation is -6.1 x 10⁻³.