"X sigma moves" - to log or not to log?

I've been trying to learn options math and am getting hung up on a basic misunderstanding. From what I have gathered, to get a single day volatility from annualized volatility, you would do something like this - var dailyVol = impliedVol / sqrt(1.0 / 365); My assumption would then be that if I want to find an "x sigma" daily move to the upside or downside, I would do the following - var newPrice = exp(log(1 + dailyVol) * nSigma) * currPrice; But when reading through options trading materials, th