Designed for use in rural Ecuador, addition and multiplication bingo games which promote number recognition and fluency in arithmetic operations are described. These skills are necessary for successful transaction at the market place where rural Ecuadorians must be able to buy goods and make change. The leader calls out a mathematical problem and learners place a bean on the correct square of their board. The winner's results are checked by the rest of the class. It is possible to involve advance and lower-level learners in the same game by allowing advanced learners to shout out the answers which the slower learners look for on their boards. The author warns, however, that if slower learners dominate, the game quickly becomes boring for the advanced players. The games have proven popular and adaptations include community bingo games with prizes. Evaluation of this method of short term learning seems to indicate that when betting is allowed, measurable improvement in mathematics skills increases. The design of both the addition and multiplication games is included. (KC)