Geometric measurement: understand concepts of area and relate to area of multiplication and addition.
Relate area to the operations of multiplication and addition. (3.MD.7)
b. Multiply side lengths to find areas of rectangles with whole-number side lengths in the context of solving real world and mathematical problems, and represent whole-number products as rectangular areas in mathematical reasoning. (3.MD.7b)
More information and the complete College and Career Readiness Standards can be found here.