Question

Question #2707b

Answer 1

`45 millionth = 45/"1 million"=0.000045`

In scientific notation, you move the decimal point to the left or right, untill you have one proper (=non-zero) digit on the left of the decimal point.

In this case it would be `4.5` with 5 moves to the right.

Now the notation works like this:
To the right:
You add `*10^"-moves"` (negative power)
To the left:
You add `*10^"+moves"` (positive power)

So in your case it would be `4.5*10^-5`

If we had a number like 45 million:
`45000000=4.5*10000000=4.5*10^7`