Question

9

Dusty found out that each grain of sand weighs 40000 or .000025 of a pound. He decides to write this
number in scientific notation.
2.5 x 10
What value should Dusty record in the box?
Record your answer and fill in the bubbles on your answer
document. Be sure to use the correct place value.

Answer 1

`n = -5`

Explanation:

Given

`Digit = 0.000025`

Required

Rewrite using scientific notation, then find n

`Digit = 0.000025`

Express as fraction

`Digit =(25)/(1000000)`

This can be splitted to

`Digit = 25 * 10^(-6)`

The first number must be between 1 and 10; hence, 25 can be expressed as 2..5 * 10

`Digit = 2.5 * 10* 10^(-6)`

Apply law of indices

`Digit = 2.5 * 10^(1-6)`

`Digit = 2.5 * 10^(-5)`

Comparing n, the given options

`n = -5`