Okay, in Microsoft Excel, we have all these functions. So I will say, Oh, these are the most popular functions. So we can do the sum function using something like this. You can go into the SL, I will say I undo all these our table, and we can do something like this sum, and then NSA savvy rubber. Okay, then we get a total of the first day oh boy here on the first column here. So it's a variable column.

So this is how we use the sum function.