I have a spreadsheet I use for breaking numbers down for use in a journal
entry.
Each cell calculates a percentage of a number for me. When I ask for a
total of the columns to prove that my debits and credits are equal - I get
equal numbers; but if actually add everything in one column and then the
other the columns are not the same. Somehow the rounding makes it appear as
though it balances - then when I key the entry into my accounting software it
doesn't balance.

I'm confused as to how to control the rounding in the cells.