Question

Which number’s estimate written as a single digit times a power of 10 will have a negative exponent?

A. 0.0023967
B. 1,023,967
C. 10,239,670
D. 23,967

Answer 1

Answer: Choice A

Reason:

`0.0023967 = 2.3967 * 10^(-3)`

The exponent of -3 tells us to move the decimal point to the left 3 units to go from 2.3967 back to 0.0023967 again.

The other answer choices involve positive exponents.

For example,
`23,967 = 2.3967 * 10^(4)` for choice D. The decimal point in 2.3967 moves to the right four spaces to get back to 23,967 again.