Euclid's Algorithm

This tool for visualizing of Euclid's algorithm (programmed by Jason Davies) comes from Underground Mathematics. Fawn Nguyen has written a fabulous narrative on how she used it as a notice-and-wonder activity with her sixth graders. What she did would work just as well with high school students. All you need to get started are two positive whole numbers.

Factoring Trinomials

Factor trinomials while looking at the graph of the quadratic. Some of the examples are not factorable. It is also possible to turn off the graph. There are options to time yourself or to print a worksheet of randomly generated factoring practice problems.

• Problems where a = 1
• Problems where a is not necessarily 1

WolframAlpha

Type in, for example, an equation you want to solve, a function you want to graph or the names of two cities. You will want to keep playing. This video by Robert Talbert gives some ideas about how a math teacher or student might begin exploring.

Bloomington High School's Math Practice

I have used both the factoring practice and the radical practice successfully with my Algebra 1 students. Practice is also available for FOILing and times tables.