I had no cash with me when I went to the bank to cash a check. When he cashed the check, the teller made an error, switching the dollars and cents part of the payment. I.e., he gave me as many dollars as I should have gotten cents, and as many cents as I should have gotten dollars.
I didn't notice until I bought a pack of gum for $0.50, and saw that i then had left exactly twice as much money as the check was written for.
What was the amount of the check?