I have two snapshots of data in big tables on two different sheets. Basically the sheets have identical content but the numbers are from different moments of time. I need to compute the delta between these moments of time.

How to easily compute delta (e.g. subtract each cell on sheet 1 from sheet 2 and store result on respective cell on sheet 3)? Non-numeric cells have identical content and should be copied as-is.

I'd prefer something that works with LibreOffice Calc but being able to do this with MS Excel is acceptable.