In mathematics, adding numbers, items or amounts produces a sum. The word also refers to a group of arithmetic problems given as a classroom assignment. As a verb, to sum is to find the total of added amounts.
Sum can be used to describe a particular total, as in the sentence "He paid a huge sum of money." It can also be used to describe an indefinite amount or series of amounts, as exampled by the sentence "She deposited several small sums." Sum also refers to a whole formed from two or more parts and summarizing, or summing up, means to make a concise statement of the gist of a matter.