? "oh! There is a hole in the wall. Li Ting's humorous class once again attracted her daughter.
At the beginning of the course, Mr. Li Ting introduced the arithmetic method of missing items with the story of rabbit tooth extraction. Her daughter's eyes are full of worship. "The teacher is very severe. I can see at a glance that the rabbit has lost several teeth, but what is missing and what is missing? " Although my daughter first came into contact with the problem of addition and subtraction in kindergarten, she still didn't understand such technical terms. "Leak, that is to say, how many * * *, how much less now. For example, there used to be 10 apples on the table, but now there are only 8 apples left. How many apples are missing? I draw pictures to help my daughter understand. The daughter quickly said that there were two apples missing. " Then how did you work it out? "I asked." 10-8 = 2 "The daughter confidently answered why 10-8? "I pretended not to understand and asked." Subtraction should be used when subtracting. As our teacher said, 10 is bigger than 8, so use 10-8! Don't you even know it's that simple, mom? You are so stupid! "After that, my daughter began to laugh." There are as many teeth on the rabbit as there are under it. Now, because I eat too much sugar, I get tooth decay and my teeth will fall out. Dr. Hippo calculated rabbits according to their original number of teeth and their present number of teeth. This method is called leak detection. It doesn't matter if you don't understand now, you will understand when you are older, "I continued, and my daughter nodded in ignorance.
When Li Ting asked her deskmates to observe each other, her daughter said, "I won't eat sugar in the future, and I don't want to lose my teeth. It's ugly. Mom, I won't eat sugar in the future, won't I lose my teeth? " "Teeth will be lost because of eating sugar, and children will have to change their teeth when they grow up. There is a children's song in your book, "When a baby grows up, it will change its deciduous teeth, and when a tadpole grows up, it will lose its tail", which means that when you change your teeth, it means that you have grown up. My daughter looked at me puzzled.
? On the issue of repairing the wall, two and a half blocks turned into a turn, which she didn't quite understand. I just picked up a piece of paper on the table, separated it from the middle, and then put it back together. With specific things, my daughter soon understood. She calculated carefully. Although she didn't do it right in the end, she was very serious in the whole process. After class, I asked my daughter, "Do you have any good ways to solve the hole in the wall?" The daughter said, "You can fill the wall in a different color and then count!" " Although her daughter's method is a little low, she still tries to do it.
Careful observation shows that the arrangement of bricks on the wall is regular, and the number of sandwich bricks is the same.
We can calculate the hole in the wall by putting a pendulum, drawing a picture, counting it, estimating it.
Mathematics is everywhere in our life. Where there is a hole to find knowledge, mathematics has beauty you can't imagine.