The math problems of large classes can be added or subtracted within 20, such as 10+8= 18, 20-2= 18 and so on. You can also make some simple answers, such as eight students standing in a team to do exercises. Which one are you in front of? This kind of question is to test the child's thinking ability and is different from the previous addition and subtraction. Another example is 12 chickens lined up, including a big cock, the sixth from the front, and several chickens behind. It is correct to use 12-8=4 chickens.

Mathematics ability should be cultivated from an early age, because it is related to children's logical thinking ability. Early childhood is a critical period for the development of cognitive ability. During this period, children gradually formed the concept of number, which aroused their great interest in learning and mobilized their enthusiasm for learning. Therefore, as parents, we must know how to grasp this critical period. Research shows that the development of primary school students' mathematical ability is closely related to their mathematical level when they first entered school.