I’m not asking about saving the Calc and closing it at that point.
I’m interested in clicking on something so that all additions/changes up to that point are now saved into the Calc, but want to keep it open and continue working.
With Excel the link to do that is in the upper left.
You didn’t say which version of LO you are using. In all the versions I have used, save has been at menu File → Save. Continue working.
You can also use Cntl + S, or just click on the “floppy disk” icon in the tool bar.
Version: 6.0.7.3 (x64)
After your post I checked and it does have File >Save.
(I assume “Continue working” is your statement and not part of the File >Save command).
Thank you for the quick response.
You assumed correctly.
Aside – Please don’t post a comment as an Answer. It confuses us. 
If this answer helped you, please accept it by clicking the check mark 
to the left of it. If this resolves your problem, close the question, that will help other people with the same question.