Sum numbers with result previous sum

[preclix]

Hello,

how sum numbers with result from previous sum? (without edit formula manualy)

If I sum cell with sumbutton (1+1=2), but if i want to sum 2 from previous sum with other numbers it doesnt work.

Example:
Select 2 (previous sum) with number 1(below) and empty cell, press sumbutton=show in empty cell only 1. Not 3

Thank you

[Lupp]

Please make fully clear (by an example):
-1- What you have in what cells. (The content, not just what’s displayed.)
-2- What you will enter in what cell.
-3- What you expect to get in what cell(s).
-4- What you are addressing as the “sumbutton”.
-5- What you had selected befor clicking on it.