IF statement across multiple sheets

[jaylundquist]

Hello,
I am trying to create an IF statement, or another formula if that's better, that would calculate improvement across multiple months. We'll use pushups as the item we are tracking. I need to make a formula that will show a persons improvement for the rest of the year with the baseline being December. Say a person did 20 pushups in December and then on the next sheet for January they did 25 pushups and February they did 30. however in March they regressed and only did 15 pushups. I need the main sheet to be able to sort through which months have been filled in and subtract the most recent entry from December. so if only January has been filled in the cell will say 5. if it is now February the cell will say 10, and once March is filled in it will say -5 on the tracking cell. I feel like this should be fairly simple however I haven't been able to get it to work on my own and have been unable to find any examples.
Thank you in advance for any help.

 

[jasonb75]

Assuming that the number of pushups is in B2 of each sheet, you would need to use something like

=IF(March!B2<>"",March!B2,IF(February!B2<>"",February!B2,IF(January!B2<>"",January!B2)))-December!B2

Unfortunately there is no practical alternative to the long formula method for what you want to do.