math
posted by carolyn .
Sam wants to make concrete blocks that are 24 inches by 24 inches by 4 inches thick. How man blocks can he make from 1 cubic yard of concrete

assuming the concrete is in liquid form and poured into moulds
each block is 24x24x4 or 2304 cubic inches
number of cubic inches in one cubic yard
= 36x36x36 = 46656
number of blocks = 46656/2304 = 20.25
He can make 20 blocks, (not enough for 21)