Derp can work out prime numbers very quickly. Press the green flag and he will ask you what number you want to star with, and a number to end with. He then works out whether all the numbers in between the two you entered are prime or not, and adds them to the list. ********** For the first time, online mode is actually faster than turbo mode when downloaded. If downloaded, click edit, start, and then set single stepping to turbo mode. ********** Changelog: 1.0 - Working program 1.0.1 - Now skips checking for factors when it is over half of the number it is checking (for numbers over four) for up to two times the speed 1.0.2 - Added pause button 1.1 - Once the program has worked out that a number has more than two factors, it will instantly put it in the non-prime number list. This makes it unbelievably faster. 1.1.1 - Fixed a bug not letting it work online and now you can set the min and max to the same number