Common Core State Standards
CCSS.Math.Content.4.MD Measurement and Data
CCSS.Math.Content.4.MD.A Solve problems involving measurement and conversion of measurements from a larger unit to a smaller unit.
CCSS.Math.Content.4.MD.A.3 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.