A scientific calculator has two 'log' buttons on it. These are marked log and ln. The log key is used for calculations of the form \({\log _{10}}x\). For example, to work out that \(\log 10000 = 4\) ...

NO practical man ever saw the least difficulty either in the idea of logarithms to a given base or in the use of common logarithms in arithmetical work. But if the practical man becomes inquisitive as ...