When I add numbers in a column, sometimes I'm not getting the correct total.
I've cleared the cells of all formuals, and have re-entered the SUM formula
(sometimes clicked the icon) and still nothing. To test for accuracy, I will
delete a number and the total may or may not change. My workboods has about
30-40 sheets, so testing and totalling every sheet after every entry would be
very time-consuming.