counting series of figure

例句：

1. 1. We need to count the number of people in the room.
   我们需要数一下房间里的人数。
2. 2. The teacher counted the students as they entered the classroom.
   老师在学生们进入教室时点名。
3. 3.Counting by hand is a useful skill for children learning mathematics.
   手算是一种有用的数学技能，对学龄儿童来说。