Aiyo, muz be you guys misinterpret wat he asked you to do lah...there's NO WAY he can go wrong lah. It works this way, watever you type in, the system will total up til they get a single digit number(the three nos. you typed) & use 9 to subtract. For example you typed in 168 = 1+6+8= 15, s0 1+5 = 6...use 9 - 6...you get the answer 3.
Lim Wei Ming
Why you guys so surprized? Its simply a mathematical gimmick.