400
Juan's mom uses 2 cups of flour to make a loaf of bread. There are 4 loaves of bread on a tray. There are 5 trays on a cart. How many cups of flour does she need to make all the bread?
2 x 4 x 5 =
2 x (4 x 5) = 4 x 5 = 20 20 x 2 = 40 cups of flour
(2 x 4) x 5= 2 x 4 = 8 8 x 5= 40 cups of flour