University of Illinois
University of Illinois: Rollin' Rollin' Rollin'
This page from the University of Illinois is the beginning of a series that demonstrates the difference between the mean and median of a group of numbers. The sites use bar graphs to display the data.
Khan Academy
Khan Academy: Creating Dot Plots
Practice creating dot plots. Dot plots are very similar to frequency tables, but they make it easier to see the data. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.