In early 15th century Europe, the letters 'P' and 'M' were generally used. Nicole Oresme's manuscripts from the 14th century show what may be one of the earliest uses of + as a sign for plus. The Egyptian hieroglyphic sign for addition, for example, resembled a pair of legs walking in the direction in which the text was written ( Egyptian could be written either from right to left or left to right), with the reverse sign indicating subtraction: Though the signs now seem as familiar as the alphabet or the Hindu-Arabic numerals, they are not of great antiquity. Plus and minus are Latin terms meaning 'more' and 'less', respectively. Their use has been extended to many other meanings, more or less analogous.
In addition, + represents the operation of addition, which results in a sum, while − represents subtraction, resulting in a difference. The plus sign + and the minus sign − are mathematical symbols used to represent the notions of positive and negative, respectively.
