The number in the top right is the amount of money that needs to be given. You need to give exact change or else you lose and you must do it as quickly as possible too. There are 10 rounds of this before the game ends.
I got bored so I just made a Scratch game relevant to my line of work at the moment. The only US tender included are the most common: $100.00, $50.00, $20.00, $10.00, $5.00, $1.00, $0.25, $0.10, $0.05, and $0.01. The coins are not to scale with the bills. This game was made 11 June 2024.