The students make groups and get a small whiteboard and marker. They pick 3 ‘unlucky’ numbers within the range being practiced and write them on their whiteboard. Every group starts with 5 points. The teacher then sets a timer and the students repeat them within a time limit. When the timer goes off, if they picked the last number called as ‘unlucky’, they lose one point.

For later rounds, the number of ‘unlucky’ numbers the students have to pick can increase. Another option (perhaps for the final round) is for the students to pick unlucky numbers for another group.