Derek need to buy 4 sheets of plywood for $9 each and some boxes of nails. He has $60 to spend. If each box of nails costs $5 at most how many boxes can he buy?
4 (plywood sheets) x 9 (price of sheets)= 36$ 36$ (price of four plywood sheets) - 60$ (total sum) = 24$ 24$ : 5$ (price per box) = 4.8, but he can’t but a fraction of a box so he can only buy 4 boxes of nails