Math Is Fun Forum

Hi everyone, I have a formula in an Excel sheet which works fine to find the sum of two cells, (      =ABS(C26-D26)*100    ) which would have say 150.25 or 1.2609.However, although it shows the sum,

1   I would like a formula that would show the answer as either positive or negative depending whether the 2nd cell is lower or higher than the primary cell?

2   I would like the same in another cell to show the difference as a percentage + or -  ?

3   Also i would like to know a good place to learn more about Excell formula's?

Thanks