Say you have a big rectangle. You can split that big rectangle up into little rectangles, say unit rectangles whose areas are 1, and then count up all those little rectangles to find the area of the larger rectangle. So for instance: I have a rectangle that has an area of 4ft^2 I can split up that rectangle to smaller rectangles of 1ft^2 Then I can count how many smaller rectangles I have and deduce the area of the larger rectangle form that -> 1ft^2 * 4 = 4ft^2