About Fifty, from BoardGameGeek:
Fifty, which was also released as Count Up, is a number-based game in which players pick numbers that will ideally bring them points.
At the start of a round, all players secretly write down five numbers between 1 and 49 on their player sheet, with some numbers being restricted. Someone then starts counting up from 1 to 50, and if you wrote down a called number, raise your hand. If you are the only player who wrote that number, you become the leader and continue to count, scoring 1 point for each number that you count. As soon as exactly one other player raises their hand, they take over as leader. If two or more players raise their hand at the same time, they cancel one another out, and the current leader keeps counting.
When the count reaches 50, the round ends, and after playing four rounds, whoever has scored the most points wins.
