Solve problems involving measurement and conversion of measurements from a larger unit to a smaller unit. Apply the area and perimeter formulas for rectangles in real world and mathematical problems. For example, find the width of a rectangular room given the area of the flooring and the length, by viewing the area formula as a multiplication equation with an unknown factor.
How long would it take to mow a very large lawn with a push-mower?
Can two rectangles have the same perimeter but… different areas!?
So… just how many kids could we cram onto the playground?