First, correct some of your mistakes. Idiot and idiot are terms used in intelligence tests. Children will definitely not reach the height of idiots! Idiots are all retarded. I am so low that I don't know how to eat and drink, I can't speak, I don't recognize colors at all, I don't know my parents, I don't know if I am a man or a beast. Only the simplest physiological response. Such as crying in pain and other basic physiological reactions.
So, don't bring a hat to your child. In addition, about IQ test. This is absolutely not allowed. Webster's intelligence test for children is a scientific intelligence test recognized all over the world. Besides, don't worry about the kind of tests that the school teachers do themselves. Even in Webster's intelligence test for children, the subjects are all children over six years old, not including children over five years old! And many children are not in the mood for that kind of test at all. I answered at random.
How did he know that you seldom taught him this fact? When I was 5 years old, I had no idea what 1 plus 1 was. From the perspective of child psychology. Five-year-olds can't think backwards at all. 1+2=3.2+ 1= What? Of course he doesn't know. Because the order is reversed. Because children are too young to think backwards. Maybe the other kids will. That's also copying mechanically! I didn't even realize it myself!
About children going to preschool. Children are not encouraged to go to kindergarten too early. Running more and going out to see more are the most important things. My brother is already a master tutor and a full professor! He looked like a fool when he was eight years old! Running around all day.
The so-called learning should match the child's intelligence and understanding. What does a five-year-old know? Let him recite Tang poems. He just parrots the words and doesn't understand the meaning of these poems at all. Zhai Hongshen began to recite Tao Te Ching, Four Books and Five Classics at the age of five. I didn't know what it meant until I was in my thirties: "Tao can be Tao, not surprising." Zhai is a famous sinologist and enjoys a good reputation all over the country!
I suggest you don't let your children go to preschool too early. It's no use learning a poem or two. Simple addition and subtraction? It's no use! Cultivate children's good character, courage not afraid of difficulties, good creativity and imagination! These benefits are endless! To put it bluntly, education is largely deceptive! Education teaches children to learn knowledge, but it doesn't teach them how to be a person and what kind of person they become! I haven't received higher education myself, but I teach people who have received higher education!