`10^2 = 100` `log_10 100 = 2` `log10^x = x` `10^(logx) = x` `logA + logB = log(AB)` `logA - logB = log(A/B)` `logA^n = nlogA` `lnA = log_eA` where `e = 2.718281828459...` `lne^x = x` `e^(lnx) = x` `ln A + ln B = log(AB)` `ln A - ln B = log(A/B)` `ln A^n = nlnA`