In the evening, I saw a problem in the Olympiad Book: the number of apple trees in the orchard is three times that of pear trees. Master Lao Wang fertilizes 50 apple trees and 20 pear trees every day. A few days later, all the pear trees were fertilized, but the remaining 80 apple trees were not fertilized. Excuse me: How many apple trees and pear trees are there in the orchard?

I am not intimidated by this question, but it can stimulate my interest. I think the apple tree is three times as big as the pear tree. If two kinds of trees are to be fertilized on the same day, Master Lao Wang will fertilize "20×3" apple trees and 20 pear trees every day. In fact, he only fertilizes 50 apple trees every day, which is 10, and the last 80 trees. Therefore, Master Lao Wang has been fertilizing for 8 days. 20 pear trees a day, 8 days is 160 pear trees. According to the first condition, there are 480 apple trees. This is to solve the problem with the idea of hypothesis, so I think the hypothesis method is really a good way to solve the problem.

Chapter 2: Interesting Mathematics

Today, I finished my math homework and watched "Enlightenment of Mathematics" in the Mathematical Grand View Garden. The king of ancient Greece asked Archimedes, a famous mathematician, for a shortcut to learning mathematics. Archimedes wrote down two numbers on the paper:11,1. "111"means "unique" and "100 1" means "consistent". It means: there is no shortcut to learning, so you can only persevere.

I thought it was very interesting, so my mother and I found a few more figures like this:

"23456789" means "lack of clothes and food (10)"

"7086" means "falling apart"

"2468 10" means "unique"

"999" means "a thousand evils get one"

Math is really interesting. I like it more and more