Tick tock. Teachers can prepare several class lists in advance, let children tick the names of boys or girls, and add up the numbers to get the number of the gender in the class.
Draw a circle The teacher prepared some pictures of fruit in advance, and asked the children to circle the fruit in green or other colors. Finally, they counted the circles.
Write orthography. The teacher named all the students in the class, asked them to write orthography, one for each student, and finally counted orthography.