The sides of a whiteboard are 3 feet by 1 foot. How many 2 inch by 2 inch Post-it notes will be needed to cover the entire whiteboard?

Board:

Width = 3 feet = 3*12 = 36 inches

Height = 1 foot = 1*12 = 12 inches

36 in (board width) / 2 in (posit width) = 18

12 in (board height) / 2 in (posit height) = 6

Area = base * height

Area = 18 post-its wide * 6 post-its height = 108 post-its