My teacher has offered bonus points if we can use the same formula in two
different cells to obtain different results. This is for an accounting
worksheet with entries similar to:

Columns E&F Columns G&H Columns I&J
Debit Credit Debit Credit Debit Credit
5 0 5 0 10
0
0 3 7 0 4
0
0 3 0 7 0
10

My column I formula: =IF(E11-F11+G11-H110,+E11-F11+G11,0)
My column J formula: =IF(E11-F11+G11-H11<0,-(+E11-F11+G11-H11),0)

Only one of the I & J columns can have an amount above zero in it and the
other has to be zero. The formula in both I and J must be the same.