Compute a sum (3)

I believe the answer is:

add

(Other definitions for add that I've seen before include "problem for hyperactive children" , "Put together (numbers)" , "Increase" , "Include" , "Sum up; say further" .)

I've seen this clue in the USA Today.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.