National Council of Teachers of Mathematics
Nctm: Figure This: A Shard or Two
Archaeologists have just uncovered an ancient plate. They need your help to determine the original size of the plate. Try this challenge where you use concepts of symmetry and estimation to uncover the solution. An activity from the NCTM...
National Council of Teachers of Mathematics
The Math Forum: Multicultural Math Fair: Srinivasa's Spheres
Straightforward lesson that introduces students to pi by letting them measure real objects and solve a challenge problem. Includes instructions and a "Data Sheet" for keeping track of measurements. Available in English and Spanish.