In my CI 402 education class we were asked to go on a "scavenger hunt" to find applets on the internet that could be useful for us to use in our classrooms someday. They varied from applets like plotting graphs to playing factor games. These were all fairly elementary applets that we felt we could use in the middle and high schools. I was just thinking and wondered if there were any applets that could be found for number theory. Sure enough I found a few websites and here is one that I'll share with you guys.

This is kind of a neat site, it's for basic computation number theory that has tutorials as well as an applet that allows you to plug in two numbers and find the GCD as well as plug in numbers mod a different number and you can figure out what it is just by clicking calculate. Pretty neat and and easy way to figure out "something mod something" or the "gcd of something" if you forgot or don't want to do the calculations.