I can remember what it is, god how could i forget!
Okay, look at this right?
10 = 10 - 1 = 9
11 = 11 - 2 = 9
12 = 12 - 3 = 9
...
99 = 99 - 18 = 81
All of the numbers are in the 9x table, try it! Nw look at every 9th number (9,18,27,36,45,54,63,72,81,90) all of them have the same symbol each time... haha, im so proud of myself for remembering it haha, i figured it out ages and ages ago, it was frustrating i was up for hours thinking ' i need 2 find out how it does it' hahaha!