Answer by
Vladlen (358)

OK, for example you want to calculate how much is 25% simple interest on 100$ (can be virtually anything). 25% means that it's 25/100 (percent mean it's out of 100). Now you just multiply 100$ by 25% or 25/100 (100$ x 25/100 = 25$). In other words you just multiply by number of percents and divide by 100.