Activity
University of Regina (Canada)

University of Regina: Math Central: Surface Area to Volume Ratio

For Teachers 9th - 10th
Students will investigate the relationship between surface area and volume and their application to the inner workings of real life organisms.
Activity
National Council of Teachers of Mathematics

The Math Forum: Surface Area of a Sphere

For Students 9th - 10th
This site from Dr. Math at the Math Forum provides a concrete way to prove to students the formula for the surface area of a sphere.