[[Image:log.png|thumb|right|px=200|Logarithm with various bases. Note that the legend has an error: it confuses the base 2 and base e lines.]]
'''Logarithm''' of a [[number]] is the [[exponential]] power to which you raise the base to obtain the number.
The arrival of pocket-sized electronic [[calculator]]s brought an end to the practical use of the slide rule or the table of logarithms. A calculator can compute a logarithm to ten places in less time than it takes to turn to the right page in a book-sized table of logarithms.
[[categoryCategory:mathematicsMathematics]]