- Bonnie Lee

# Teach Kids Concept of Perimeter with Homemade Cookie-Cutters

In the age we live in, we can purchase everything. We could find cookie-cutters of all shapes and sizes. But I miss the handmade quality of homemade goods. You can teach your kids to make their own cookie-cutters, so they can take ownership of their work and learn about perimeters at the same time.

Ingredients

**Aluminum Sheets **can be purchased at hardware stores

**Scissors** are used to cut the aluminum sheets.

**Strings** to find the perimeter of your drawing

**Ruler** to measure the length of the string

**Scotch Tape **to close the cookie-cutter

**Drawing** the shape that you want your cookie cutter to be

**Needle Nose Pliers **(Optional) to bend the aluminum in a precise way

**3rd Grade CA Common Core Math Standard**

3.8 Measurement & Data : Solve real-world and mathematical problems involving perimeters

(1) Go to a hardware store to buy thin sheets of aluminum. I got a sheet of medium weight aluminum that measures 9 1/4" x 12" from the student store at Art Center for $9. You could also get pre-cut strips from True Value Hardware store in Pasadena for about $1 each.

(2) Cut the aluminum into strips that measures 0.625". With a string, I measure the outer edge of my drawing which happens to be a pineapple. You can use any simple drawing/ silhouette. By measuring the string, I'll find the perimeter of my pineapple. I'll also figure out how much aluminum strip I need. Since my pineapple has a lot of details, I had to tape two aluminum strips together to create a longer one.

(3) With a set of pliers, bend the aluminum strip to conform to your image. You could just use your fingers if pliers are not available. When you finish, use Scotch tape to close the overlapping aluminum strips. An experienced cookie-cutter maker told me that the tape held up quite well for years! If you want to get fancy, you could puncture a hole and use a set of rivet.

Ta-da! I'm ready to use my pineapple cutter to make some sugar cookies.

**Next time**: I'm working on how to teach kids to have a good understanding of x, y, z coordinates through 3D printing.

**5th Grade CA Common Core Math Standard **5.1-5.2 Graph points on the coordinate plane to solve real-world and mathematical problems.