Find area of composite rectangles (rectilinear figures) by counting unit squares. There are two ways students can find area by counting unit squares. The first, is to give students a figure with the squares drawn. Then students just have to count to find the area. The second, is to give students square tiles, which they can use to tile the figure, then count the number of tiles to determine the area.

Intro to area and unit squares by Khan Academy

Compare area with unit squares by Khan Academy

TODO: This exercise is about comparing areas. Find one for determining areas as well.

Conclude by giving your students this challenge, then this one. The first puzzles is quite easy, the second quite difficult! Students should make sure the figures will have the same area before moving pieces around.

Conclude by leading this investigation:

Armenian Rug Puzzles (logic)

by MathPickle

3.MD.C.6: Measure areas by counting unit squares (square cm, square m, square in, square ft, and improvised units).