Did you know that 0.99999 (repeating) is the same number as 1? Here’s a simple proof:

- Let a = 0.9999…
- Multiply by 10: 10 * a = 10 * 0.9999…
- Simplified: 10a = 9.999…
- Subtract a: 10a – a = 9.999… – 0.9999…
- Which means: 9a = 9
- Divide 9: a = 1
- Voila: 0.9999… = 1

Of course, there’s always the simpler:

- 1/3 = 0.3333…
- Multiply by 3: 1 = 0.9999…

## One Comment

The magic of “Related posts” shows me that I was fascinated by this exact thing 4 years ago.