I have a simple table in a Google Docs and now need to sum the whole column but can't find button like in Sheets:
I have adjusted the focus of your question to emphasise the workaround you seemed to be asking for rather than the button that you also asked for since (a) one question at a time is generally for the best and (b) I doubt adding a SUM button to the menu bar in Docs is practical.
What I do find practical is the process I often use, for Word, that involves Excel even though Word has a lot of Quick Parts for actions of the kind you requested. That is to copy the table (without Total) into Sheets, apply the SUM button in Sheets and then copy the table (with Total) back into Docs.
I was looking for the same thing, and discovered there is now a Google Docs addon which allows you to select multiple table cells and click a button to calculate the sum (or multiply, divide, etc.). Unfortunately it isn't able to update totals automatically when the values change (you still need a manual step for that) but it might still be a time-saver.
Please find the documentation here
there is no other option listed then the standard SUM() function.
SUM(value1, [value2, ...])
- value1 - The first number or range to add together.
- value2, ... - [ OPTIONAL ] - Additional numbers or ranges to add to value1.