Read the dictionary definition of sum. All definitions for this word.
1. the whole amount
2. a quantity obtained by the addition of a group of numbers
3. the choicest or most essential or most vital part of some idea or experience
1. the gist of the prosecutor's argument
2. the heart and soul of the Republican Party
3. the nub of the story
4. the final aggregate
1. the sum of all our troubles did not equal the misery they suffered
5. a set containing all and only the members of two or more given sets
1. let C be the union of the sets A and B
6. a quantity of money
1. he borrowed a large sum
2. the amount he had in cash was insufficient
7. determine the sum of
1. Add all the people in this town to those of the neighboring town
8. be a summary of
1. The abstract summarizes the main ideas in the paper