how do i add or subtract 2 lines

125
152
how do i add these two numbers?

1 above the other

Hello,

Maybe you should look in the docs → LibreOffice Calc Guide

or here → What is a Spreadsheet?

Assuming cell A1 contains 125 and cell A2 contains 152 then enter in A3 =A1+A2 (or =SUM(A1:A2) to sum a range from A1 to A2).

And read the Calc guide Ratslinger pointed to…

Good grief! In excel, you just put a - sign in front of number and hit sum!

Care to elaborate?