AFFIRMATIVE Quantity

, or Positive Quantity, one which is to be added, or taken effectively; in contradistinction to one that is to be subtracted, or taken defectively.—The term affirmative was introduced by Vieta.

Affirmative Sign, or Positive Sign, in Algebra, the sign of addition, thus marked +, and is called plus, or more, or added to. When set before any single quantity, it serves to denote that it is an affirmative or a positive quantity; when set between two or more quantities, it denotes their sum, shewing that the latter are to be added to the former. So + 6, and + a, and + AB, are affirmative quantities; also + 6 + 8 + 10 denote the sum of 6, 8, and 10, which is 24, and are read thus, 6 plus 8 plus 10. Also a + b + c denote the sum of the quantities represented by a, b and c, when added together. It seems now not easy to ascertain with certainty, when, or by whom, this sign was first introduced; but it was probably by the Germans, as I find it first used by Stifelius in his Arithmetic, printed in 1544.

The early writers on Algebra used the word plus in Latin, or piu in Italian, for addition, and afterwards the initial p only, as a contraction; like as they used minus, or meno, or the initial m only, for subtraction: and thus these operations were denoted in Italy by Lucas de Burgo, Tartalea, and Cardan, while the signs + and - were employed much about the same time in Germany by Stifelius, Scheubelius, and others, for the same operations.