Find the Area of Rectangles Using Multiplication

(C) Determine the area of rectangles with whole number side lengths in problems using multiplication related to the number of rows times the number of unit squares in each row

3.MD.7 Relate area to the operations of multiplication and addition.

3.MD.7.D Recognize area as additive. Find areas of rectilinear figures by decomposing them into non-overlapping rectangles and adding the areas of the non-overlapping parts, applying this technique to solve real world problems.