The world's most difficult third-grade math problem, the third grade, the unpredictability of mathematics is often beyond our ordinary thinking. The study of mathematics has been going on. Let's take a look at what the most difficult third-grade math problem in the world is.

Goldbach conjecture, the world's most difficult third-grade math problem of 1, can be roughly divided into two kinds of conjecture (the former is called "strong" or "double Goldbach conjecture" and the latter is called "weak" or "triple Goldbach conjecture"):

Every even number not less than 6 can be expressed as the sum of two odd prime numbers;

2. Every odd number not less than 9 can be expressed as the sum of three odd prime numbers. Consider expressing even numbers as the sum of two numbers, each of which is the product of several prime numbers. If you put your life

The title "Every big even number can be expressed as the sum of a number not exceeding the prime factor and a number not exceeding the prime factor of B" is recorded as "a+b". In 1966, Chen Jingrun proved "1+2", that is, "any big even number can be expressed as the sum of a prime number and another number whose prime factor is not greater than 2". It is only one step away from guessing "1+ 1" right away.

The third question examines the rigor of students' reading and pays attention to the word "round trip".

The fourth question, involving price comparison, is to calculate the meal expenses spent in two canteens and then compare them. Many children finally fell behind, that is, 684 >; This step is indispensable.

The fifth question is to test reading ability. It should be noted that the second condition is "the last two classes donated 543 copies", which is different from the first condition.

The sixth question, in addition to price comparison, also involves the ticket purchase scheme. Children with strong logical thinking can design four schemes. Scheme 1 is to take the train back and forth, scheme 2 is to fly back and forth, scheme 3 is to take the train (plane) when you go and fly (train) when you come back. After calculation, the round-trip fare alone is more than 3,500 yuan.

Seventh, the phenomenon of translation and rotation should be expressed accurately.

The eighth and ninth questions, "The problem of sum multiples", know the sum and the total multiple, first find a multiple, that is, first draw a line chart to clarify the relationship between multiple and sum, then apply "sum/total multiple = 1 multiple" to find a multiple, and then calculate the corresponding answer according to the conditions.

The tenth problem, the problem of normalization, is to find a single quantity first and then compare it.

The eleventh question examines the children's ability to read and understand the meaning of the question. The meaning expressed in the middle long sentence must be understood in order to do the right question.

The twelfth question, "Equivalent Substitution Problem", should guide children to draw a line diagram or write an analytical formula: 3 notebooks+1 exercise book = 14 yuan, 1 notebook = 2 exercise books. Therefore, if "3 notebooks" are replaced by "3*2 exercise books", there will be 7 exercise books = 14 yuan, and the unit price of 1 exercise book can be calculated.

Questions 13 and 14, like question 90, are all "questions of harmony and the times".

The fifteenth question, the distribution problem, is to find the total first and then redistribute it.

Sixteenth question, make money, let children know "selling price-buying price = profit".

The seventeenth question involves the understanding of the meaning of division, that is, the dividend is several times the divisor, the quotient is several times, the dividend is the quotient, and the divisor is several times. The quotient divided by the divisor is equal to the dividend.

There are two ways to solve the problem 18, one is to calculate according to the vertical puzzle type, and the other is to treat it with "poor questions". Adding a 0 at the end of a number is equivalent to expanding the number by 10, so the difference between the number obtained and the original number is 9 times, so dividing 80 1 by 9 is twice the original number.

Question 19, check reading ability, especially the last question is about how many degrees of power can be generated, and get an approximate value. Many students lose points because they get an "accurate number". Question 2 1 is also about finding the divisor.

Question 22. The analysis process is a bit complicated, but the topic is not difficult. Let's examine the ability to explain problems with mathematics.

Question 23, "the problem of difference times", no one in the class did it right. According to the principle of "the same increase and the same decrease", it is inferred that after Tian Qiang and Liu Wei deposit the same amount of money, the difference between their deposits is still (828-200), and at this time, Tian Qiang is twice as much as Liu Wei's deposit, indicating that the difference between their money is twice, so a multiple can be obtained.

This kind of problem is the same as the "double problem". It is necessary to guide children to draw line drawings, clarify the relationship between difference and multiple, and calculate the multiple of 1

Question 24, like question 23, is a "difference question" and a consolidation of the previous question.

Questions 25 and 26 examine children's ability to read and understand the meaning of the question, and can also guide children to draw pictures and clarify the meaning of the question.

Question 27: Examine the children's ability to analyze problems with mathematics, and compare the amount spent on different tickets.

Question 28, "Inverse inference method", uses the result obtained by the wrong algorithm to calculate the unknown number, and then correctly calculates the correct result.

Question 29: Understand the meaning of division. Dividing the number reduced by the dividend by the number with less quotient is the divisor. Find the divisor, and then calculate the correct quotient according to the correct number.

Questions 30 and 3 1 are all about discounts, so how much money is saved, that is, the amount spent without discounts-the amount spent after discounts. Both algorithms should be understood by children.

The thirty-second question is the price comparison. We should calculate the amount spent on different schemes and compare them.

Questions 33, 34 and 35 are all "sum multiples", and the total divided by the total multiple = 1 multiple.

Question 36. Guide the children to draw and make clear the meaning of the question.

The thirty-seventh and thirty-eighth questions involve the problem of "difference multiple". If the thirty-eighth question is not an integer multiple, it should be supplemented by the method of "more refunds and less supplements". That is, "less than 4 times 3", "difference +3" should be multiplied by 4.

Topic 39, the problem of "equivalent substitution", that is, "the sum of three multiples of A and five multiples of B" = three times of B (A+B)+ two numbers.

Question 40, "Planting Trees", add 1 at both ends.

In short, since the reform of college entrance examination, from elementary school to junior high school in recent two years, mathematics has paid more and more attention to the cultivation of children's thinking ability and the ability to solve practical problems by using mathematical thinking. The key is to clarify the thinking of solving problems and let children do more thinking training questions, which is conducive to cultivating children's logical thinking ability.

The world's most difficult third-grade math problem 2 1, the most embarrassing math problem in history, add a straight line.

The following is an Olympic math problem in the fourth grade of China primary school. It is said that 99 people got the answer wrong or thought it was impossible to finish. In the figure below, you can only add a straight line to divide the graph into two triangles.

Take some time to think about the solution first, and remember to look at the most embarrassing math problem in the world with unconventional thinking. The answer is on page two.

2. The most embarrassing math problem in history, matchsticks.

Look at the picture below. These are two quadrangles composed of eight matchsticks. The requirement is that only two matchsticks are moved to make them square, and the matchsticks cannot be broken. Can't bend, just like the first question above, let's play cards according to common sense!

Study it first. If not, go to the second page to check the answer.

3, the most embarrassing math problem in history, take the grid as an example.

The figure below consists of 16 squares. The question is: from the starting point to the end point, how can we not repeat all the squares, walk sideways and walk out of the squares?

? The most difficult third-grade math problem in the world is the conversion of three time units. As long as you keep two progress rates in mind, you will basically not make mistakes.

How much is 7 o'clock? First, according to the fact that one hour is equal to 60 points, it is inferred that seven hours is 760 points, and 760 points is 42 points, so correspondingly, 760 points is 420 points.

In addition to the simple conversion of hours, minutes and seconds, there is also a more difficult topic: there are both time and minutes.

A topic like this needs to be calculated by addition. First, the conversion of time component is measured, and then the two parts are added. This problem needs to convert 2 hours into 120 points, plus the following 30 points, and the final result is 150 points.

Judging from the math homework of junior three students at the beginning of school, the overall situation is relatively poor. Is it holiday syndrome? I went crazy for a holiday, but I couldn't enter the state after school started, which led to a mess of writing and many wrong questions.

To avoid the influence of holiday syndrome, primary school students must be guided to close their hearts and return to class as soon as possible. The bad habits formed during the holidays should not affect the study after school starts. This requires parents to guide their children, make clear their learning goals and enter the state in time.

Primary school knowledge is relatively simple, but there are still many wrong questions for careless children. It is best to digest what you have learned in time, and correct and make up for any problems immediately.

The study habits of primary school students are very important. If they form the habit of being careless and not serious, it will inevitably affect their academic performance. Parents need to help their children develop good habits of standardized writing and independent thinking. Once good study habits are formed, parents basically don't have to worry about their children's study.