Question

a quarter weighs about 0.025 pounds. what is this number written in scientific notation?

Answer 1

It would be 2.5E-2 or with the power of 10 it would be 2.5 x 10^-2

Answer 2

2.5×10^−2

Multiply 0.025 by 100 to get 2.5 (must be ≥1 but it must also be <10)

100 has two zeros and you get the 2 for the power of 10.
The −2 is because it is a decimal you are converting.