Question

How do you express `0.0042` in scientific notation?

Answer 1

`42 * 10^-4`

Explanation:

Scientific notation was created for when numbers are too large to write down, particularly when many digits are zeros. In our case,

`0.0042 = 42/10000 = 42/10^4 = 42 * 1/10^4`

Recall that `1/a^b = a^-b` and vice versa,

so we can write `42 * 1/10^4 = 42 * 10^-4`.