5.5 * 10^6
you just move the decimal point to the right 6 places
5500000.
if you're starting from a number (let's say 3712905) and you want to make it look like 5.5 * 10^6 you do it like this:
3712905.
but you want the decimal to be just to the right of the 3
you have to move the decimal over 6 places
3.712905 * 10^6