.40 is 40%. Easiest way is to take a simple 10 % of 25,000? that's 2,500, right. then to go from 10 to 40 is simply to multiply by 4. so 4 x 2500 is 10000. Or think in what the question is asking. 40 % of 25000 = .40 divided by 25000 = 10000' in math " of " means divide