Wristbands and hand stamps are fine until someone asks “how many did we actually sell?” Numbered tickets answer that by themselves: if the night started at ticket 3301 and finished at 3496, you sold 195 — and the stubs in the tin should agree. That is the treasurer’s reconciliation done before the sausage sizzle is packed away.
It also makes pre-sales simple. Send books home or sell at the office all week, jot down which numbers each class or seller took, and the door list takes care of itself.