OMG, paying the Civilian Staff ... the nightmare of being Orderly Officer at Tengah.
Accounts issued, meticulously, the correct number of notes and coins according to their formula [in the days before spreadsheets] - everyone's pay, to the $/c, and then combined in a bloody great bag. And one was paying c. 200 people!
So if one carelessly gave Mr Wong 2 x $5 instead of 1 x $10, you were doomed ... you ran out of change. I learned the hard way, and subsequently always carried out that duty with wallet/pockets full of small bills and coins to correct any errors upstream!