Actually its simple. Its just narrowing the numbers down by color. See when the house pops up some of those numbers are not the same color as the first page and some of the numbers are not even listed on the first page. Well it seems simple anyway
I hate to spoil the trick, but it really is easy. On the first page every color has 5 numbers. On the house page, each color separates those 5 numbers into 5 separate houses. So on the first page when you pick the color of your number, you've narrowed the possibilities to 5 numbers, and then on the house page, when you choose the house, you pinpoint the number you chose. They change the colors around in the houses to throw you off and all the rest of the clicking is smoke and mirros. Sorry if I ruined the magic for some of you.