On the morning of the 18th, the national finals came, and the participating teams ushered in a nutritious breakfast of "bread/steamed bread/porridge/soybean milk". In order to avoid causing pressure to the students, the organizing committee ordered the accompanying parents not to eat at the same table with their children, and any one parent present was enough to make it difficult for the whole table of children to eat.

Parents feel reasonable, for the sake of their children, but they are very cooperative with the requirements of the leading teacher.

After the meal, I didn't have a long rest, and the bus of the Olympiad Organizing Committee drove to the hotel and drove the team to the examination room of Jingyuan Middle School. At this time, the traffic jam in Yanjing is not so serious, it takes about 40 minutes from Guangming Road in the Fourth Ring Road to Jingyuanzhong, all the participating students have arrived at about 9:00am, and they enter the examination room 30 minutes early at 9:30am.

This is an exam comparable to the college entrance examination, and the students sitting in the examination room are basically the "champions, top eyes, and tanhua" of science in various cities, and at the moment they are competing for the title of "national".

The number of invigilators in the national competition is sufficient, with 288 students occupying all classes in the junior high school, and there are as many as 12 classes in the first grade of Jingyuan Middle School alone. If it is a small city like Nanhua, there are only four classes in one grade, and I am afraid that even the classrooms of the high school will have to be used as examination rooms, which shows that the candidates' positions are deliberately opened.

When the papers and manuscript papers are sent, the front test papers cannot be seen in the back, and the test papers on both sides cannot be seen in the middle, which eliminates the possibility that the candidate will become a giraffe.

Tick Tick Tick ...... No pen is allowed before the exam, and the only noise from the large quartz clock is the one.

The upcoming finals are being clocked in seconds.

Jingle Bell !!!!!!!!!!!!!!!!Bell Bell

The crazy bells played the march of the duel.

"Alright, let's start writing and answering questions."

The teacher's notice was obviously a bit behind, and the students only recognized the bell and did not recognize him. They had begun to calculate on the scratch paper as soon as the bell rang, and in the silence they had already prepared their ideas for solving the problem. In particular, Riki, who was warned twice before starting to write, wrote even more hard after the bell rang.

The basic knowledge paper is to test the pairs of 2πr, s=πr^2, v=1/3sh=1/3πr2h, h=3v÷s, circular side length, area, cone volume, height, trapezoid, parallelogram, ...... Variants of various formulas, and combined applications. It doesn't require much problem-solving thinking, but the amount of computation is a little large.

At the top, the first question [1.714.285÷0.37÷2.7×1.7×0.7=__________. 】

How do students calculate this kind of question? It really doesn't take much thinking, you can only do hard calculations, which can be calculated sooner or later anyway, but hard calculations are very time-consuming.

If you use your brain a little bit according to the routine, and see that there are decimals, turn them into fractions, or turn the whole formula into decimals 714.285*1.7*0.7/(0.37*0.27), and multiply them all by 100 to eliminate decimals, and you may be able to make the calculation less difficult by relying on small skills. After some painstaking calculations, the final number came out - [850.85]

Continue to write the next question, it's still a disgusting decimal problem-

[2. There is an average of 34 even numbers, if one decimal place is kept, the number is 15.9, and if two decimal places are kept, the number is _________.] 】

If you don't want to waste time on this decimal calculation problem, then choose from the ten numbers of 15.85-15.94, and omit 15.90 with [keep two decimal places], and the probability of guessing is 1/9.

Well, don't move so many fancy intestines. If you have strong computing power, you can directly use 15.9*34 to round up and even one, and then remove 34 from the four adjacent numbers.

However, everyone usually calculates in the Olympiad like this: the minimum and maximum values are used to determine the integer range, and 15.85*34=538.9/15.94*34=541.96 is only 540 in the range that meets the "even" number.

540/34≈【15.88】

Fill it in and go straight to the next question......

If he did, there was no doubt that the student had made a mistake!

Go back and take 542 to check, 542 is divided by 34 quotient ≈ 15.941≈15.9, so [15.94] is also eligible! The answer is two numbers [15.88 or 15.94]!

-- This question has killed a lot of people.

Riki wrote the answer to [15.88 or 15.94]. He didn't find the answer because he was very sensitive to numbers, but he didn't use so many tricks, and since the basic knowledge test test was about calculation ability, he simply used the second stupid method to calculate.

Don't desert, concentrate and continue to do the question.

[6. The largest square in the fan is drawn with an area of 30 square meters, find the area except the square]

Fan Area, Square Area, Outside Area...... Riki estimates that this question can open up the gap between many students.

――I don't even have a picture for this question, so I have to draw it myself!

Riki didn't bring a ruler with him, but it wasn't difficult for him to draw a standard fan shape on the paper. If other students can't draw with an ordinary ruler, they have to slowly construct a fan shape in their minds......

Limu's calculation ability is not strong, and it can only be regarded as middle and upper; I didn't have strong logical skills, but I also learned software programming; The only advantage over other students is problem-solving experience and mental focus.

High concentration means seriousness, and doing things seriously improves work efficiency.

His mental power of up to 14 points is running at an extremely fast speed!

After 60 minutes, I finally finished all the questions, and submitting the paper early in this national competition is tantamount to pretending to be 13, which is even more shameful than selling yin! Therefore, he honestly checked the three sides of the test paper, and finally found two trap questions that were the same as the second question.

I can't help but sigh: although the difficulty of the finals does not increase, the traps are frequent but harmful.

******

What's even more harmful is the cheating lecture. After the primary school exam, I took 40 minutes to drive back to the hotel, ate for half an hour, rested for an hour and a half, and took 40 minutes to attend a lecture in the auditorium of the examination hall not long after I got up.

"There is so much free time and I don't give my children a good rest, so I have to engage in this kind of formalism." Riki sat in the corner of the student auditorium of Jingyuan Middle School and complained.

"Uh-huh."

"After the exam tomorrow, I will visit the city, and the day after tomorrow it will be [***], museums, science and technology museums, and the day after tomorrow Peking University lecture hall ceremony...... How do I feel like my life is being squandered by them? ”

"yes, yes."

The girl sat next to her, and she should say every word Riki said, and she nodded in agreement no matter what she said.

"Hey, don't put your face so close! You don't care, I don't care, I'm so tired of being careful, I don't even have to be a 'confidant' lalala-" Riki pressed the girl's round forehead with both hands, and pushed her back to her seat with all the strength of the milk.

The girl is suicidal and can't be too harsh on her, but Riki doesn't want to be pestered by her all day because of her compassion. No matter how you look at it, the trip caused quite a bit of trouble. Fortunately, threatening her with words such as "confidant", "going home", and "moving to a foreign country" can still achieve a certain deterrent effect.

When Muzi sat down obediently, all the participating students settled down, played the "Welcome March", and the leaders came to the stage...... The lecture finally began.

Lectures are very boring for both students and leaders. Each time, he repeatedly told the history of the Olympiad, the spirit of the Olympiad, and the situation of the national Olympiad, and then explained the next winter camp and the International Olympiad IMO. In order to motivate the students who are about to be selected and those who have not had the opportunity to be selected, they will also actively participate in future CMO competitions...... This was followed by the student representatives' testimonials.

Obviously, the student representative of the speech is not yet the turn of Xiao Rimu. After all, he had not been notified before the lecture, and it was impossible for him to go up to the lecture without prior practice.

Although it was not his turn to give a speech, the host was still so frightened that he was terrified.

"Next, I would like to invite the student representative of Jiangnan Province, Wujun Muzi, to make a speech on the competition - everyone is welcome!"

Riki looked at his neighbor in surprise, and Muzi stood up and walked up from the aisle to the podium amid warm applause. After two attempts, she took a deep breath and began to speak:

"First of all, I would like to thank my teachers, because it was their teaching that made it possible for me to achieve this result. I would also like to thank my classmates, it is because of the competition between each other that my math scores have improved greatly. I would also like to thank my family for their support and encouragement when I was struggling, they gave me the confidence to solve my difficulties. Finally, I would like to thank mathematics for the great pleasure it has brought me and given me the opportunity to stand here and speak......"

- No wonder she's wearing a school uniform today.

Riki was annoyed by his hindsight, and a very bad feeling kept coming out of his heart.

The speaker of Jiangnan Province is obviously Muzi. Olympiad has always adhered to the tradition of "merit-based selection", "girls first", and "foreigners first". Muzi is tied for first place with him, and she is a girl and has a foreign name......

"Thank you, my dear classmate Riki-"

When she heard Muzi mention herself, Riki immediately flashed a bitter smile of "sure enough", and her chagrin and worry instantly turned into reality.

"Thank you for the conversation he had with me in the past, thank him for saving me on the plane, and thank him for the ...... of beep beep at night."

Although she speaks in a proper manner, there is nothing wrong with her words, and it is entirely a narrative about intimate friendship. But Riki's brain still automatically filters the information related to itself...... In fact, except for a small part at the beginning and end, she spends almost all of the text on her neighbor, Riki.

The students, who were already almost sleepy, were moved by the legendary experience that Muzi said, and from time to time they cast admiring glances at the little bean sprouts next to her seat.

(This kid is a fierce man who dares to do artificial respiration when others vomit!) Hmm...... It's probably a gaze full of this meaning.

Muzi's procrastination speech was pulled off the stage and became the second episode of the trip. The lecture took two hours for the students and another forty minutes for the return trip, and the competition was much more hectic with a lecture.

******

The second is the thinking ability test.

If it is disgusting to put traps in the basic knowledge test, then it is common to put traps in the thinking ability test. The second exam of the Olympiad finals is undoubtedly the stage that can best widen the score gap.

The teacher is confident that he will be able to stump many people in the second paper, and it will certainly be fine to fill in the blanks, but it will be a bit difficult to get a score of more than 40%. The second paper can be used for the next half of the candidates, and the other half of the students will receive the bronze medal. Those who get 40%~60% of the scores are probably silver medals, and the students who get more than 80% of the scores can be said to be rare, and those who get 90% of the scores are simply unique!

Just as there were no perfect marks the year before and no perfect marks last year – there will be no perfect marks this year!

But there is just one person among the contestants, who has rich experience in solving problems, and also has problem-solving methods and problem-solving thinking that include the four stages of primary, elementary, high and large......