You enter a number in the box, then you put a number. Example: Putting 2 will return that is a prime number. But putting characters, negative numbers or non-prime numbers will return that it isn't prime. EDIT: you can clear the screen by putting /clear
I actually ported Lua code that i found on Blockly (https://developers.google.com/blockly/), so it's a little bit fast. It took me like 1-2 hours making this, so i hope you like it :P Links that i used: For loop - Wikipedia: https://en.wikipedia.org/wiki/For_loop Blockly | Google Developers: https://developers.google.com/blockly/ Primality test - Wikipedia: https://en.wikipedia.org/wiki/Primality_test#Naive_methods
