Invite your child to find lots of circle shapes around your home. Then have her practice drawing circles of different sizes. Once she is familiar with numbers and measurement, introduce the concepts of diameter and circumference (see definitions below), and invite her to discover their relationship herself.
- Pi (π) 3.14 The number, rounded off, that represents the ratio of the circumference of a circle to its diameter. In other words, the number of times the diameter goes around the circumference. If a circle’s circumference measured 3.14 inches, its diameter would be 1 inch.
- Circle: a curved line equidistant from a central point.
- Circumference: the perimeter of a circle.
- Diameter: a line segment across the center of a circle.
☞ What You Need:
Measuring tape or 1-foot length of string marked in inches, colored markers, colored or lead pencils, ruler, plain paper, construction paper, hole punch, yarn, small circular items
- Use a colored or lead pencil to trace around a circular item on a piece of paper.
- Write the object’s name above the circle.
- Measure the circle’s circumference. Round-off to the nearest quarter inch. Write “circumference = (measurement) inches,” under the circle.
- Measure the circle’s diameter. Round-off to the nearest quarter inch. Write “diameter = (measurement) inches,” under the first measurement.
- Discuss how the diameter fits a little over three times around the circumference.
- Choose a new page and repeat steps 1–4.
- Collect finished pages, add a colorful construction paper cover, and punch three holes down the side.
- Bind the pages together with yarn and write “My Circumference and Diameter Book” on the cover.
Download the PDF: Make a Diameter and Circumference Book