Your checkbook shows a balance of $413. your bank statement says you have $373. assuming you are missing just one transaction, what is the amount of the transaction you are missing?

If your account shows a balance of $413 and you only have one missing transaction, with a final balance in your account of $373, then:

$413 + x = $373
x = $373 - $413
x = - $40

So, the transaction is a withdrawal (or loss) of $40.