Intellectual development of primary school students: problems and answers of classical mathematical intelligence
1. Say apple.
Number ten baskets of apples according to 1 ~ 10, and take out different numbers of apples according to the number of each basket. For example, take out 1 apples from the basket numbered 1 and five apples from the basket numbered 5, * * * (1+ 10) × 65438. If the weight of each apple is 1 kg, then a * * * should be 55 kg. Because the weight of a basket is very light, it is impossible to reach 55 kg, only between 54 and 54-54.9 kg. If the weighing result is less than 55 kg times X, the lighter one must be the basket numbered X. In fact, for the convenience of weighing, you don't need to take the tenth basket of apples, you can take 45 apples at a time, up to 45 kg. If the results are weighed,
Just 45 kg, indicating that the tenth basket is light. Otherwise, the apples numbered in the basket will be light.
Many people feel that there is no solution to this problem at first, but it makes sense after telling the answer.
4. Weigh the parts.
First, put four parts on each side of the balance. If the balance is balanced, it means that the defective parts are in the other five, and it is not difficult to find them after weighing twice. If it is not balanced, it means that the bad ones are in eight. At this time, remember what is light and what is heavy. The remaining five are qualified and can be used as standards. Then put five qualified ones on the left side of the balance, and take two light ones and three heavy ones on the right. At this time, if the right end is low, it means that the bad one is in the triple and can be weighed out at one time. Other situations are relatively simple, so I won't go into details here.
[14] narrow escape
The farmer grabbed a piece of paper, immediately put it in his mouth and swallowed it. The remaining nine pieces were "dead", so the county magistrate had to admit that the farmer had caught them.
It's still alive, so we must let it go.
4. counterfeit money.
Lost 10 yuan, which is the face value of a counterfeit currency. Many people confused the question when guessing this question, but the result was wrong.
Step 5 buy cigarettes
The best way to solve this problem is to solve the "indefinite equations", otherwise we can only use the "tentative" method. Buy a box of grapes and a box of winter jasmine, and buy all the rest of the money for Harbin cigarettes. * * * You can buy 10 boxes. If you buy a box of Yingchun cigarettes and Harbin cigarettes, you can buy 12 boxes with the remaining money. In other words, customers can buy at least 10 boxes and at most 12 boxes. Let's take a look at the situation of buying 10 boxes. Let Harbin, Yingchun and Grape Smoke buy X, Y and Z boxes respectively, and we can list the indefinite equations:
29x+27y+23z=300 ①
x+y+z= 10 ②
Solve y= 10-x-z from ② and substitute it into ① to get:
2z=x- 15 ③
∵ x≤8, z≥ 1 ∴ ③ No solution.
Change 10 in formula ② to 1 1, and finally arrange it as 2x=3+4z, with even numbers on the left and odd numbers on the right, and there is no solution. Finally, change 1 1 to 12 to get: 2z= 12+x, let x=2 (even numbers only) to get z=7, y=3, and then let x=4 to get z=8, y= X can't be any bigger, so there is only one answer, namely:
Buy 2 boxes of Harbin brand, 3 boxes of Yingchun brand and 7 boxes of grape brand.
Will (male name)
You exchange horses and ride them. Pay attention to whose horse is slow in the question. Fast and slow are relative. It is the same thing to ask whose horse is slow and whose horse is fast.
A quick answer.
None of them flew, but everyone else did.
2 10, dead fish is fish.
(3) Not necessarily. If you cut along the diagonal, there are three corners left; If you cut from an angle to the opposite side, there are four angles left; If you cut from one side to the adjacent side, there are five corners left, one more than the original.
(4) 9 people, totally * *11person. The front, back and middle of the problem are relative.
5] You don't need one, just two people face to face.
[6] There are four more. This is a game where 1 person catches 9 people.
Once impossible, there will be no sun in the middle of the night.
Three words, namely: national, international and song.
⒏ Divide the socks.
Divide each pair of socks in two, and each person can take a pair.
Where is the money?
Two fathers, two sons, actually three people (three generations).
5. ask for advice.
People's heads are exposed above the top of the stone, which means "right". So you should go to the right.
Tangram puzzle
Tangram, also known as Tangram and Wisdom Board, is an intellectual toy circulated among the people in China. It evolved from the banquet in the Song Dynasty, initially as an indoor game for literati, and later evolved into a folk jigsaw puzzle. According to Lu Yiqing's "Cold Land Miscellaneous Knowledge" in Qing Dynasty, there are several pictures of Song and Huang banquets, which are divided into twenty-five styles and become sixty-eight styles. Several pictures of butterflies are very clear, but the system has been modified, and triangles are staggered into hooks, such as butterfly wings. Its formula three, its system six, its dozens of three, its variant, where more than one hundred. Recently, there are seven clever diagrams, the formula is five, the number is seven, and there are more than a thousand kinds of changes. The body is simple and changeable, and the tools of the game are enough to dispel boredom and break the silence, so secular people like it. "Now the jigsaw puzzle is cut into five small Pythagorean shapes by a square and pieced together into various things, such as people, animals and plants, pavilions, cars, boats, bridges and so on. You can play alone or with many people. Some important geometric relations can be clarified by using puzzles, and its principle is the "complementary access principle" in ancient arithmetic.
Tangram consists of the following seven boards. The complete pattern is a square: five isosceles right triangles (two small triangles, one middle triangle and two large triangles), one square and one parallelogram.
/kloc-One of the most popular jigsaw puzzles in the 0/9th century is the jigsaw puzzle. The popularity of Tangram is probably due to its simple structure, simple operation and easy understanding. You can use jigsaw puzzles to spell out your own designs at will, but if you want to use jigsaw puzzles to spell out specific patterns, you will encounter real challenges. This is the fun of jigsaw puzzles.
The jigsaw puzzle has a simple structure, which easily leads people to think that it is easy to solve its problems, but this idea is one-sided. /kloc-more than 0/600 patterns can be put together by puzzles, some are easy to spell, some are quite mysterious, and some are specious and full of contradictions.
What about mentally retarded children?
Every child's development and personality are different, and every child's intelligence is also very different. But for a mother to swim, the child's intelligence needs to be developed in time and exercised with her parents. So what should her mother do when her intelligence is not as good as other children's? What about children with mental retardation?
What about mentally retarded children?
1, memory, digital computing ability: including children's attention training, attention and memory training, memory enhancement training, memory enhancement training and multi-ability collaborative training. These trainings are very effective for the treatment of mental retardation. I hope parents will read it carefully.
2. Sports ability: Train children's proficiency in big movements such as climbing, turning over, sitting, standing, walking, running and jumping, and also train children's flexibility and accuracy of limbs, from training children to grasp big and close things and fiddle with things, to fine movements such as unbuttoning and threading needles, and finally to complicated movements such as disassembling things. Adjuvant therapy, exercise is definitely indispensable.
3. Language ability: When children can't speak, they should talk to them and communicate with them emotionally. Let children listen to music, dialogues, children's songs, stories, etc. Enhance children's language perception and understanding ability, and teach children to pronounce single tones in entertainment until they are taught simple words and sentences.
Causes of children's mental retardation
1, genetic factors, if parents are mentally retarded, children are also prone to mental retardation. According to statistics, if the father is mentally retarded and the mother is normal, then the probability of his child's mental retardation is less than 10%. But if the mother is mentally retarded and the father is normal, then the probability of her child's mental retardation is greater than10%;
2. Nutritional factors Malnutrition, especially protein deficiency, will have a negative impact on the development of the brain. If the mother is severely malnourished during pregnancy, especially protein deficiency, the brain development of the fetus will be poor. If a baby suffers from severe malnutrition within six months after birth, it will also have a great impact on his intellectual development.
3, childbirth factors, if the child encounters dystocia at birth, or has intracranial hemorrhage, or once severely suffocated, it will affect the child's intellectual development, resulting in lifelong mental retardation.
4, disease factors, if the mother is infected with a virus during pregnancy, such as rubella virus, it will not only cause abnormalities in some organs of the fetus, but also affect the intelligence of the child; If the baby born a few months has encephalitis, meningitis, pneumonia, septicemia, etc. It will affect the development of the brain and cause mental retardation;
What about mentally retarded children? Children's intelligence can be improved by communicating with their parents. When the baby is mentally retarded, he can usually play some intellectual games with his parents, which is also very effective. There are many reasons for children's mental retardation, because heredity or any serious disease that children have had is the cause of mental retardation.
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