Thales saw that people were reading the notice, so he went to check it. The initial notice said that Pharaoh wanted the smartest person in the world to measure the height of the pyramid. So I went to Pharaoh.
Pharaoh asked Thales what tools he used to measure the pyramids. Thales said he only used a stick and a ruler. He put the stick next to the pyramid. When the shadow of the stick was as long as the stick, he measured the length of the shadow of the pyramid and half the length of the bottom of the pyramid. Add these two lengths to get the height of the pyramid.
Thales is really the smartest man in the world. He can easily measure the height of the pyramid without climbing to the top.
2. The story of the first three minutes of math class 2
During the Warring States Period, Qi Weiwang and Tian Ji raced, and Qi Weiwang and Tian Ji each had three good horses: getting on, winning and dismounting. The race is divided into three times, and thousands of dollars are bet on each horse race. Because the horsepower of the two horses is almost the same, and Qi Weiwang's horse is better than Tian Ji's, most people think that Tian Ji will lose.
However, Tian Ji took the advice of his disciple Sun Bin (a famous strategist) and dismounted Qi Weiwang, Ma Zhong of Qi Weiwang and Qi Weiwang. As a result, Tian Ji beat Qi Weiwang 2-/kloc-0-and got a daughter. This is an example of China's ancient substitution game theory to solve problems.
3. A short story about the first three minutes of math class
When Gauss was still in the second grade of primary school, one day his math teacher wanted to use class time to deal with some personal affairs, so he planned to give the students a difficult problem to practice. His topic is:1+2+3+4+5+6+7+8+9+10 =?
Because addition has just been taught, the teacher thinks it will take a long time for students to solve this problem. I can also take this opportunity to deal with unfinished business. But in the blink of an eye, Gauss had stopped writing and sat there doing nothing. The teacher saw it and called Gauss angrily.
But Gauss said he had figured out the answer, which was 55. The teacher was startled and asked how Gauss worked it out. Gauss replied, "I just found out that the sum of 1 and 10 is the sum of1,2 and 9,1,3 and 8,1/kloc-0. And because11+1+11+11= 55, that's how I worked it out. "
Hearing this, the teachers and students all gave Gauss a thumbs-up. Later Gauss grew up and became a great mathematician.
4. The story of the first three minutes of math class 4
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 fertilized 50 apple trees every day, which was 10, and finally 80. 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.
5. The first three minutes of Math Story 5
On this day, I read a story, asking swallows to try frogs. The story goes like this: one day, the swallow said to the frog, let's compare whose math is better. The frog agreed. Frog problem: Last Monday, I ate a pest. On Tuesday, I ate three pests. After that, I ate two more pests every day than the day before. How many pests do I eat in a week?
The swallow said:1+3 = 44+5 = 99+7 =16/9 = 2525+11= 3636+13 = 40. ?
The frog said, test me. The swallow said: I ate two pests last Monday, four on Tuesday, and then I ate two more pests every day than the day before. Ask me if I ate 56 pests a week. Before the swallow finished speaking, the frog had given the answer. The swallow said: How fast! Teach me the trick of quick calculation.
The frog asked the swallow to draw seven circles, then put a pest in the first circle, and there were two more circles behind than in front. Their order is 1, 3, 5, 7, 9, 1 1, 13, which adds up to 49. The frog put a pest outside each circle and used it again. Swallows praise frogs for their cleverness.