One of the first books to use the plus and minus signs was written in 1489, Johann Widmann’s (c. 1460-?) Mercantile Arithmetic. Originally, he used the signs + and - to indicate excesses and deficits (what we would call credit and debit) in business dealings. But some historians believe the + sign initially evolved from the French et, or “and,” because the “e” and “t” resemble the + sign.

Although they were probably used before in general mathematics, the first person known to have used the + and - symbols in writing algebraic expressions lived in the early 1500s: the Dutch mathematician Vander Hoecke. The symbols finally went into general use in England when Robert Recorde’s (1510-1558; also seen erroneously as Record) book The Whetstone of Witte was published; this is the same book responsible for bringing the equal (=) sign to the forefront of mathematics (see above).