The wonderful, whimsical mathemusician Vi Hart is back with a pair of videos that first prove, then disprove, that 0.99999… actually equals 1. Or maybe not. I love Vi’s videos, but honestly, sometimes they make me sad, because if these videos had existed while I was still in school, I definitely would have done better in math. But does 0.99999… equal 1 or not?! It’s so confusing! Thankfully Vi clears it all up in the second video.