Explore Circumference and Diameter

• Nelson, Don. “Sizing Up Trees” in Science and Children. Addison Wesley, Menlo Park, CA, May 1995.

Children learn ways to measure trees. They measure the circumference of a tree trunk with string and metersticks, the width of the tree's crown, and the height of the tree. You can point out the importance of the relationship C/D = π since it is difficult to measure the diameter directly (without harming the tree), but it is relatively easy to measure the circumference.