This design below shows, visually, how one and zero are related to each other (i.e. by rotation). Here is a mathematical proof for the same idea.
A proof that one equals zero.
Consider two non-zero numbers x and y such that
x = y.
Then x2 = xy.
Subtract the same thing from both sides:
x2 – y2 = xy – y2.
Dividing by (x-y), obtain
x + y = y.
Since x = y, we see that
2 y = y.
Thus 2 = 1, since we started with y nonzero.
Subtracting 1 from both sides,
1 = 0.
Hmmm… Clearly something is wrong with this proof. Can you figure out what it is?
Thanks to Mudd Math Fun Facts for the proof above.