According to the seating order, the first student reads 1, then the second student reads 2, and the third student applauds (it is a multiple of 3). Those who don't clap their hands or pronounce the wrong sound will be punished (casually).

Grab 30.

Students A and B can take turns to count, and only 1 or 2 can be counted at a time. Whoever gets to 30 first wins.

Colored ball

The teacher prepared a bag with balls marked with numbers in it. Let the students write down their favorite formula symbols on the blackboard: addition, subtraction, multiplication and division, then touch out the ball from the bag, and then use the numbers on the ball and the symbols written on the blackboard to form the formula.

Let's see who's quick.

Divide the class into two groups. Two groups of students are half holding numbers and half holding formulas. The teacher reads the numbers quickly and asks the students with corresponding formulas to stand up quickly. At the same time, you should stand up and see which group is faster.