0.999… repeating (or 0.9‾0.\bar{9}) is equal to 1. It’s a fact. To some, this is highly counterintuitive, unbelievable even. I’ve seen various explanations for how it works, from informal explanations to formal proofs. I recently found an interesting (not original) proof, but first I’ll give a couple less rigorous explanations. Informal arguments Tripling a third…