University of Regina (Canada)
University of Regina: Math Central: Surface Area to Volume Ratio
Students will investigate the relationship between surface area and volume and their application to the inner workings of real life organisms.
Oswego City School District
Regents Exam Prep Center: Spheres
What is a sphere? Find a definition, example images, and formulas to help you determine volume and surface area given the radius.
Khan Academy
Khan Academy: Cell Size
Test your knowledge on how to calculate cell size with this quiz.
National Council of Teachers of Mathematics
The Math Forum: Surface Area of a Sphere
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.
Calculator Soup
Calculator Soup: Sphere Calculator
This online calculator will calculate the 3 unknown values of a sphere given any 1 known variable including radius r, surface area A, volume V and circumference C. It will also give the answers for volume, surface area, and circumference...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Sphere Formulas
This site from the Math Forum provides the formulas for finding the area and volume of a sphere.