Teaching material analysis:
In life, group counting is widely used. Through activities, let children know the methods of counting in groups and experience the fun of counting in different ways in operation. And migrate to daily life as much as possible. Counting by group means counting by group (a group of objects) instead of individual objects. Children's ability to count in groups is not sudden, but developed on the basis of children's mastery of the concept of 10. If the method is proper, children's ability to count in groups can reach a skilled level, and the range can reach "100" or even more. It's faster to press a few numbers. Why? Help children understand the functional relationship that the larger the array, the less the count, the smaller the array and the more the count.