1, 4920590, the highest digit means (). Answer: 4 million. B, 400 thousand. C, 4 million. D, four tens of millions.

2. In the following paragraphs, the approximate value of () rounded to 10,000 digits is 840,000. A: 834776 .b, 844 165. 845000 pounds. d、849999。

3. The number that does not read zero in the following figures is (). 630.9 million pounds. B, 639008000. c、639070000。 d、40024077

4. The closest number to 4.25 million is (). Answer: 4249999.49999999999 4255000 pounds. d、4259088。

The fourth grade is the key to learning knowledge

It is said that children in the fourth grade are the key to learning knowledge, and we think the cultivation of habits in the fourth grade is the most important. The fourth grade has certain learning methods and a certain foundation in knowledge. They have been in school for four years, and the children have a deep understanding of the teachers who teach them. Some children already know how to treat different teachers.

They began to have a "self" and personal tendency. They began to have their own opinions. The most obvious performance is that a seemingly obedient child will stubbornly think that he is right for a different opinion and become difficult to accept the opinions of his classmates. Different opponents will make him make a hullabaloo about, and sometimes he will open his heart and sophistry for himself with his teachers' opinions and criticisms.

So the most common mistake they make is sophistry and denial, and cover up their mistakes with some cleverness. Sometimes he acts like an adult. Therefore, in the fourth grade, teachers and parents must start to take care of their children seriously, and they must not let the existing good habits be destroyed or let the children become bad.

Find out the causes of children's emotional changes.

By the fourth grade or so, children will have words like "annoying" and "annoying", and the number of such words will continue to rise. In fact, children's troubles are not only aimed at toys, clothes, hairstyles, or extracurricular reading materials. What they need is the understanding and respect of their parents. When a child is truly understood and respected, all his negative and rebellious emotions will disappear.

They are in a period of sudden emotional change, easy to get angry and angry, but also easy to be moved. Parents' understanding and respect can impress them more than giving them precious gifts.