To teach circumference, radius, and diameter of a circle, I have a few lessons that I do. One is to read aloud Sir Cumference and the Knights of the Round Table. We chart the story as we go along. (Helpful to have this done ahead of time). This is a fun book that gets the kids thinking about circles and tricks to remember the names of the parts of the circle (Lady Di of Ameter stretches her body across the circle, and the diameter is the measure of her toes to finger tips). Then we label a number of circles with diameter and radius. The next day we discuss our charts and revisit the story.
