The classroom was quiet, save for the "rustle" of pens sliding over the test papers.

In order to take care of the six children who were taking the exam, Ma Zhongguo deliberately stopped lecturing and took his four primary school students to study quietly on their own.

Lin Ping watched the six children answer the questions on the podium, frowning and biting the tip of their noses for a while, as if they were in difficulty, and then their brows were stretched and smiling, as if they had found a way to solve the questions.

Lin Ping looked at this group of children in a daze, and then laughed stupidly. The children of their youth are really simple and cute, their joys, sorrows and sorrows are all written on their faces, and you can tell at a glance whether they are happy or angry, sad or happy. You don't have to try to figure out what they're thinking, it's all written on their faces.

And what about adults?

An important sign of maturity is that "joy and anger are invisible", which means that people are calm and self-contained, and their feelings are not exposed. That is to say, when a mature person does something, he cannot let others see your feelings about a thing.

A lot of people say it's not hypocrisy, it's called camouflage.

Camouflage is to be able to survive better in the adult world. Pretending to greet others with a smiling face, pretending to be strong that doesn't cry.

If you are good at disguise, you will live a very tired life, but if you are not good at disguise, you will live a difficult life.

In the adult world of 18 years old, there is no such thing as "easy", but it is not necessarily true. For example, it is easy to be obese, easy to be bald, and easy to sudden death.

Exercise more, stay up late.

"Teacher!" Liu Xiangqian suddenly raised his hand, "Is this question wrong?"

Lin Ping walked over with a smile and picked up the test paper to look at it carefully, and then returned it to Liu Xiangqian: "There is no mistake in the question, you can think about it again." ”

This test paper was written by Lin Ping in accordance with the principle of "6+2+2", that is, 60% of the basic simple questions, 20% of the advanced questions, and 20% of the Olympiad questions.

Lin Ping felt that Liu Xiangqian and his five junior high school students had no problem making 60% of the basic simple questions and 20% of the advanced questions, and it was easy to use their brains carefully to score these 80 points, and 20% of the Olympiad questions would be difficult.

These 20% of the Olympiad questions are carefully selected by Lin Ping, including a slightly simpler primary school Olympiad chicken and rabbit cage, water intake and drainage, as well as slightly more difficult proof questions, and even the famous "Gauss 5050", that is, from 1 to 100 questions, this question is put as the finale to the last question, if these students can't find a good solution to this problem, then they can only go from 1+2, +3, +4...... Start adding and work your way up to 100, but this is a time-consuming thing.

"Note that the exam is 90 minutes long, and now an hour has passed. Lin Ping opened his mouth to remind.

At this time, everyone also achieved the last 20% of the questions, and they all frowned. Only Wang Yige is different, according to Lin Ping's observation, he completed the previous simple questions and elevated questions twenty minutes ago, and entered the stage of overcoming the Olympiad problems early.

"The final question is a very, very difficult question, difficult and low score, the teacher specially came out to test your mathematical thinking, if you feel that time is limited, you can pick a feeling of the topic to think. ”

Lin Ping was afraid that the questions would be too difficult and would make the students doubt their lives, so he persuaded him with good words.

"Teacher!" Liu Xiangqian raised his hand again.

"What's wrong?"

Liu Xiangqian stood up and held up the test paper and read: "A swimming pool, there is an inlet pipe and an outlet pipe, it takes 4 hours to fill all the water, and it takes 5 hours to release all the water, first open the inlet pipe, when the water in the pool occupies a quarter of the pool, then open the inlet pipe and the outlet pipe at the same time, and ask how long it takes to make the pool reach two-thirds full?"

"What's wrong?" Lin Ping asked.

"It's a good swimming pool, isn't it sick that you put water in while you release it?" Liu Xiangqian scratched his head and said, "This is a waste of water, teacher." ”

Lin Ping smiled and asked Liu Xiangqian to sit down, and then said: "Students should understand that mathematical problems are not equal to practical problems, and mathematical problems are mostly a theoretical hypothesis. ”

In the past, Lin Ping also felt that the person who came up with this kind of problem had a poisonous brain, which was not in line with the reality of life at all. It wasn't until Lin Ping had a mobile phone, when he played with his mobile phone while charging, that he realized that everyone really knew how to do stupid things like "getting out of the water and entering the water".

It is much wiser to compare the problem of "water into water" to the problem of "charging electricity", for example: you now have 23% of the battery left in your mobile phone, which is only enough for two and a half hours, so you decide to charge your mobile phone, play while charging, and the charging speed is known to be 15% per hour, assuming that the electricity consumption speed and charging speed have been in an average state throughout the whole process, then how long does it take you to charge and play while charging?

If you look at it, it's much more realistic.

"There are still 15 minutes before the end of the exam. Lin Ping looked at his watch and reminded.

"Teacher, I'm done. ”

At this time, Wang Yige stood up from his seat and handed the test paper to Lin Ping's hand.

The other five children all looked at Wang Yige with a look of incredulity.

"Show me, show me if he has some empty questions. Liu said with a probe in his head.

"Do your own well, people have really done it, and they are full of writing. ”

Saying that, Lin Ping showed the test paper a little.

"Hmph, Meng, it must be written blindly. Liu Xiangqian muttered unconvinced.

Lin Ping glanced at the test paper in general, and was surprised in his heart, not to mention right or wrong, this Wang Yige actually did all the questions. Lin Ping hurriedly turned to the last problem, which was the problem of adding from 1 to 100 in elementary school, which was widely known as the famous mathematician Gauss.

And now Wang Yige's test paper answer is impressively written: 5050.

That's the answer to this question.

Lin Ping couldn't help but ask excitedly, "How did you come up with the answer to this question in such a short period of time?"

At this time, Liu Qingmei on the side also did this question, but she was using the stupidest method, starting from 1 to add 100 one by one.

Wang Yige came up with the answer to this question quickly and correctly, isn't that contemporary Gauss!

The future is limitless!

"Forehead......" Wang Yige scratched his head, and then said honestly: "Teacher, in fact, I saw this question in the storybook that my father bought for me, and then I saw that it was exactly the same, so I wrote the answer on it......"

Lin Yiping also scratched his head speechlessly, okay, Bai was excited.

"Then do you know the method of this question?" Lin Ping asked again.

Wang Yige nodded: "Well, I know, from 1 to 100 can be seen as 0 to 100, so 0+100=100, 1+99=100, according to this law, that is, 100 divided by 2, there are a total of 50 100s, and there is a middle number 50, so it is 50X100+50, which is equal to 5050."

"Well, if only you learned the method. Lin Ping said encouragingly.