Mary Ann Sommers, age 14, of Camden, N.J., for her question:

WHAT ARE LOGARITHMS?

Logarithms are numbers, usually grouped in a table, used to reduce complicated multiplications and divisions to additions and subtractions and to do other problems.

A logarithm is known in algebra as an exponent.

A Scottish mathematician named John Napier prepared the first published discussion and table of logarithms in 16 41 D Jobst Burgi of Switzerland independently discovered logarithms about the same time.

About 1622, an English mathematician named Edmund Gunter conceived the idea of making equal logarithmic scales on strips and multiplying and dividing by sliding one strip along the other. This idea forms the basis for the slide rule.