Since two loaves of bread need 2 1/2 cups of flour, then how many cups do six loaves need? since 2 * 3 = 6, then the amount of flour for two loaves multiplied by 3 will be the amount needed for six! 2 1/2 * 3 = 7 1/2 Now, to find the amount of flour left over, all you need to do is subtract 7 1/2 from the amount of flour in the bag!