Simplify rational expressions that contain rational expressions within their numerators or denominators. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

This site from the University of Saskatchewan provides an explanation of similar triangles, the Pythagorean theorem, and the distance between arbitrary points in a plane. Example problems for each of these concepts are provided.

Find the lcm (least common multiple) of pairs of integers. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.