Amazing Website

I found this website on someone elses blog but I'm still allowed to talk about it if I link them right?

So this is the most amazing website! They have literally listed every number from 0-9999 and said what is special about each. As someone who as a child in moments of boredom attempted to write out as many numbers as possible I realise how much time this list must have taken (I never got so far as 9999!). I'm pretty sure Pythagoras would have been extremely proud!

So I haven't explored this page nearly enough (I think it would take years!) but so far I have already learnt what a Kaprekar number is. It is when you square a number and split the result into two numbers, add them and you get your original number - for example:

9 sqaured = 81                             8 + 1 = 9

9999 sqaured = 999800001        9998 + 00001 = 9999

Pretty cool right?!