Roofing shingles are sold by the "square." A square can cover an area of roof that is 10 ft long and 10 ft wide. A home improvement store sells shingles by the square or by the bundle. The area of a roof is 2160 square feet. Find the minimum number of squares needed to shingle this roof. Round up to the nearest square.
2160 ft^2 * 1sq/(10ft*10ft) = 21.6 sq
now round up