As a percent is out of 100% or 1 (as a whole number), the best thing to do is multiply it by ten, until you get a whole number. As you cannot have a decimal in a percentage. 2.45x10= 24.5. This is still a decimal, so you need to multiply it be ten again, 24.5x10= 245.
Therefore, 2.45 is a percent is 245%
