When working in Excel Online, which formula will add up the data in cells A1 through A10?

a. = A1+A10

b. = A1-A10

c. = sum (A1-A10)

d. = sum (A1:A10)

The answer is D. The SUM function lets you add all the values along the specified cells. To use the SUM function, you type the equal symbol and the word "sum" then a parenthesis. Inside the parenthesis are the cells you want to add-up. Specify it from the first cell to the last. Add a colon in between to two cell locations. So the right formula to input in finding the sum of all the values from A1 to A10 is = sum (A1:A10).