There was many ways to fix bingo cards in the old days.
Sammy Arbino would send Bingo Betty into a hall with a walkie talkie. As the numbers were called he would print the card. He would have a coverall in about 30 to 35 numbers. He would send it into Bingo Betty. She would wait until the last number to win the big prize ( usually the 50th number ), then holler bingo.

Halls instuted the rule that you had to have the last number called. Sammy would still print the card, all but one number. Betty would print the last number as it was called. Jump up, yell bingo, and wave the card around so the ink would dry. They used soy bean ink, fast drying. BTW, Bingo Betty weighed 350 LBs. She was tough and not too many people would argue with her. BTW 2, Betty once told me he had won 27 new cars playing bingo. Is that luck or what?
They traveled the entire east coast playing bingo.

Thats only one way.
Can't do this today because of the master card index.