Use a compass to draw three circles. Larger circles are easier to measure, so make one of the circles as big as you can, with the materials you have available. Make sure your three circles have somewhat different sizes.

Make a table with three columns: Circle Number, Diameter, Predicted Circumference, Measured Circumference

Draw and measure the diameter of of each circle, and enter your measurements in your table. Make a prediction for the circumference of each circle; you can calculate the circumference if you know how. Finally, use a string to measure the length of each circle's circumference.

How close were your predicted circumferences to your measured circumferences? Which do you think was more accurate, your prediction or your measurement? Why do you think that one was more accurate?