Baccarat: Commission

Baccarat: points

Two hands play: Player and Banker. Ace is 1, 2–9 count at face value, tens and picture cards count 0.
A hand's points are the last digit of the card total: 9 + 7 = 16, so 6 points. Totals run from 0 to 9.
8 or 9 on the first two cards is a natural: both hands stand, no third cards.
The Player draws a third card on 0–5 and stands on 6–7. The Banker's decision depends on the Banker's total and the Player's third card (table below).
The higher total wins. A Player bet pays 1:1, a Banker bet 1:1 minus 5% commission, a tie usually 8:1.

A winning Banker bet pays 19/20 of the bet: divide the bet by 20 and multiply by 19. A bet of 400 wins 380, the commission is 20.
Bets in the trainer are multiples of 20, so the answer is always a whole number.
In the sandbox you can also practise the commission alone or the payout together with the bet.