analyse
The primary school students are between the ages of, so the ages of these four children should be:, and the sum of squares equals:
If the average age of the two coaches is, then the two coaches are,
The sum of the ages of six people is equal to:
(years old)
Refine and improve
The key to solve this problem lies in:
1) The age of primary school students is between years old, which is common sense and an implicit condition of this problem;
2) This question uses the following formula:
This formula is the teaching content of junior high school mathematics. A considerable number of gifted students in grades 5 and 6 have mastered this formula, which can be considered as "transitional knowledge".
The more general form of this formula is as follows:
This is a common formula in college entrance examination mathematics.
This problem is not difficult, but also very interesting, and it is an excellent competition problem.
Finally, the author puts forward some views:
This description in the original question is not good, so it is suggested to delete the word "year" and say directly: the sum of the squares of the ages of six people is 2796.