I need to calculate 'unreconciled amount' in my check register by
looking at column B (deposit or withdrawal), column E (check amount),
column F (bank balance) and column G (reconciled). Column G will
contain either "R" for reconciled or it will be null. All
Uncreconciled (no "R") transactions must be examined to see if they
are deposits or withdrawals (column B), subtracting withdrawals from
deposits.

Can anyone help with a formula?

I currently have a helper column that is used to total the
unreconciled amounts.
(=IF($G278<"R",IF($B278="Withdrawal",$E278*-1,IF($B278="Deposit",$E278,"")),""))