Area Grids
Students calculate the area of designs on grid paper, by counting or other strategies. The calculation of a rectangular grid introduces and reinforces the concept of multiplication tables. The students also add 1/2 squares to make up whole squares. They also create a large rectangle around and enclosing a triangle and divide it in half to calculate the area. Obtuse triangles can be calculated by subtracting the exterior areas around the rectangle that encloses the triangle.