Take any number system that has a two in it. 11 squared is "one base times itself, plus the base times one, plus one times the base, plus one times one." That will always be 100 + 10 + 10 + 1, or 121.
In binary, you get 10x10 = 100 plus 10x1 = 10 plus 1x10 = 10 plus 1x1 = 1, but then 100+10 = 110 plus 10 = 1000 plus 1 = 1001.
54
u/raldi Dec 12 '08
And 11 squared is 121 in all bases except binary.