Probability, especially conditional probability, can be a slippery concept for young statisticians.  Statements that seem self-evident on the surface often require a daunting amount of calculations to explicate, or turn out to be...

In this tutorial, students learn how to do prime factorization by a few different methods, including factor trees and factor stacks. The exercises work their way up from 2-digit numbers up to 5 digits. Includes practice problems.

In this video, learn how to find the greatest common factor of two numbers. Then, see how this can be used to solve problems with large numbers. In the accompanying classroom activity, students learn to find prime factors using factor...

Watch as the National Museum of Mathematics creates an interesting series of images using ratios. This video focuses on the proportional relationship observed in fractals and challenges you to do some critical thinking using ratios and...

The telling of the Civil War from an ecological view from the National Humanities Center. The toll of life taken of young men and animals, the devastation of cities, towns, farmland, trees, and forests - all these factors are discussed...