Reggie is playing marbles with his friend. His friend arrives with 100 marbles. Each game, they bet ten marbles and whoever wins gets to keep all the marbles. After 9 games, Reggie has 90 marbles. How many games has he lost? Think carefully first, then make a decision:
Reggie has lost 10 marbles because 100 - 90 = 10. Since each game was worth 10 marbles, Reggie has lost 1 game. So, the answer is 1.