Thus multiplication and division in the power-series correspond to addition and subtraction in the index-series, and vice versa.
Addition and Subtraction of Percentages.
Addition is the process of expressing (in numeration or notation) a whole, the parts of which have already been expressed; while, if a whole has been expressed and also a part or parts, subtraction is the process of expressing the remainder.
- To find a square number which remains a square after the addition and subtraction of 5, put to our mathematician in presence of the emperor by John of Palermo, who, perhaps, was quite enough Leonardo's friend to set him such problems only as he had himself asked for.
As an illustration, we may take the elementary processes of addition, subtraction, multiplication and division.