Don't believe it?


Proof 1:

We know that:
(1/3) + (1/3) + (1/3) = 1

Since (1/3) = (0.333...):
(0.333...) + (0.333...) + (0.333...) = 1

But, (0.333...) + (0.333...) + (0.333...) = 0.999...

Therefore, 1 = 0.999...


Proof 2:

1) x = 0.999...
Multiply both sides by 10:
2) 10x = 9.999...

Subtract (1) from (2) to get:
9x = 9
x = 1

(I didn't know whether to put this under Mathematics or Philosophy. I really hope a thread about this topic hasn't been submitted before.)