To calculate this you would first have to divide 500 by 4, which is 125. This is because the denominator is the total amount of 500. Then you would multiply 125 by 3, which is 375. This is because the numerator tells us how much of the denominator, and because the denominator is the whole amount and so by dividing you are finding out what 1 of those units is and then multiplying by the numerator that tells us how many of those units.