Math Concepts: Area, Perimeter

What You Can Do: At home or in the classroom, kids can be exposed to area and perimeter in a
variety of ways. Young children can cover flat surfaces with congruent squares to determine their areas: “The area of my
bedroom floor is 64 red squares,” or “The area of my desktop is 15 blue squares.”

Kids often make the mistake of thinking that area and perimeter change proportionally, but that isn’t always the case.
For instance, a 3 × 3 square has an area of 9 square units and a perimeter of 12 units, but a 1 × 8 rectangle has an area
of 8 square units and a perimeter of 18 units. That is, the area decreased, while the perimeter increased. To explore this
idea, give students eight squares and ask them to create various arrangements of rectangles. All of the arrangements will
have an area of 8 units, but do all of the figures have the same perimeter? The answer is no, and it can be powerful for
kids to discover this on their own.

Math in the Game: The greater the area surrounded, the more points you earn. Students quickly
realize that more points are earned for a square than any rectangle with the same perimeter. Consequently, this game can
teach kids about the relationship between perimeter and area.

Related Resources:

Planning a Playground

Students have to think about area and perimeter as they place equipment on a playground that they create.

Go with Green Rectangles

This lesson allows students to investigate similar rectangles. It focuses on the relationship between the scale factor
and the ratio of perimeters as well as the scale factor and the ratio of areas.

Fair and Square: Using Concrete-Pictorial-Abstract Activities to Maximize Area

This lesson helps students understand the math of area and perimeter by creating human-sized rectangles and working with geoboards. These activities provide concrete experiences before moving on to pictorial and abstract work with area and perimeter of rectangles.