Looking for interesting questions in primary school mathematics

Sister and sister watch movies.

Xiao Fang and Xiaohua set out from home to go to the cinema. Xiaofang walks 5 kilometers per hour and Xiaohua walks 3 kilometers per hour. They started at the same time 1 hour later, my sister went home to get something, and then went after my sister. My sister kept going at the same speed, and finally they both arrived at the cinema at the same time. Find the distance from home to the cinema?

Ma Xiao Hu cooked chicken

During the Spring Festival, Xiao Mahu, a professional chicken farmer, stood in the yard and counted the total number of chickens. He decided to leave 1/2 as a gift for the People's Liberation Army 1/4 solatium and for the nursing home 1/3. After he sent the chickens away, he heard the chickens crowing in the room, only to know that there were 10 chickens missing. So I counted the chickens inside and outside the room again, and there was nothing wrong, no more, no less, just 1/2 left. Little careless and strange. What's the problem? Do you know how many chickens Xiao Mahu counted in the yard?

How many guests have come?

One day, Xiao Lin was washing dishes at home. Xiao Qiang saw it and asked, "Why do you wash so many bowls?" "There are guests at home." "How many people came?" Kobayashi said, "I don't know. I only know that each of them uses a rice bowl, two people share a soup bowl, three people share a vegetable bowl, four people share a big wine bowl, and one * * uses 15 bowl. " Do you know how many guests have come?

Weigh beads

There are 243 identical beads, one of which is slightly heavier. How many times does it take to find this bead with a weightless balance?

Divide pears

There is a box of pears in the box. The first person took half and most of the pears, the second person took the remaining half and most of the pears, the third person took the second half and most of them, the fourth person took the second half and most of them, and the fifth person took the second half and most of them. At this time, the pears in the box had just been eaten, and everyone had no pears in their hands. How many pears are there in the box?

How to group

Divide the class into 15 groups during the summer vacation. There are six students in the class, namely Zhao, Qian, Sun, Li and Zhou. How to divide each group into different surnames?

Skillfully calculate the week

October 1st this year is Monday. What day is October 1st next year? Please write a simple algorithm?

Who runs fast?

He and Xiao participated in the 100 meter race. As a result, when Xiao Wei ran to the finish line, Kobayashi only ran 95 meters. Xiao Lin asked to run again. The starting line of Xiao Wei is 5 meters behind Kobayashi's. If everyone runs at the original speed, will they reach the finish line at the same time?

Train crossing the bridge

The railway bridge of Nanjing Yangtze River Bridge is 6772 meters long, and the freight train is 428 meters long, traveling 20 meters per second. How long does it take for the whole train to cross the bridge?

Unlocking problem

Try to open the 10 lock with the same key. How many times can you tell which key matches which lock?

What is this three-digit number?

There is a three-digit number, ranging from 400 to 500. One digit is 3 larger than the hundredth digit, and ten digits are 5 smaller than one digit. What is this three-digit number?

Calculate age

Xiaoming's father is 50 years old and Xiaoming is 22 years old. Will Xiaoming's father be twice as old as Xiaoming after too many teenagers?

How many floors does this building have?

Teacher Wang recently moved into the teachers' dormitory. One day, Mr Wang stood on the balcony and looked down. There are three balconies below and five balconies above. What floor did you say Mr. Wang lived on? How many floors are there in the teachers' dormitory?

How many athletes are there?

With a loud noise, the athletes who participated in the 1500m final rushed out of the starting line and ran along the circular track. Lin Lin also participated in the final. There are five athletes running in front of Linlin and five athletes running behind Linlin. How many athletes participated in the1500m final?

Who caught the fish?

Xiao Ming, Xiao Fang and Xiao Li go fishing together. When they got home, there were 15 fish in their car. Everyone catches the same number of fish. This pile of fish has 1 big fish weighing 5 kg, five weighing 4 kg, four weighing 3 kg, three weighing 2 kg and two weighing 1 kg. One * * * is 45 Jin. No one can remember who caught the big fish. Xiao Fang only remembers that he caught two 1 kg fish in one net. Who caught that big fish weighing 5 Jin?

Find a pattern

Please carefully observe the number rule in each line below, and then fill in a number in brackets to make it conform to this rule.

( 1) 1,5,9, 13,( ),2 1,25

(2) 1,3,9,27,( )243,729

(3) 1,8,27,64,( )2 16,343

(4) 1,2,4,7,( ) 16,22

(5) 1,2,6,24,( )720,5040

(6) 1,3,7, 15,( )63, 127

(7) 1,2,5, 10,( )26,37

(8) 1,4,9, 16,( )36,49

(9) 1, 1,2,3,5,8,( )2 1,34

( 10)2,3,5,7,( ) 13, 17

( 1 1)3 12,423,534,645,( )

( 12) 122 1,2332,3443,4554,( )

( 13) 1232 1,23432,34543,45654,( )

College mathematics problems

Now I'll introduce you to a math problem in college. When students hear that this is a university problem, they should not be afraid. In fact, if you use your head and think in another way, you can work it out. Here's the question.

There is a 22-digit number, and its unit number is 7. When you multiply this 22-digit number by 7, its product is still a 22-digit number, but the single-digit number 7 is moved to the first place, and the arrangement order of other 2 1 digits remains unchanged. What is this 22-digit number?

Tip: If the number is expressed in letters, the formula is: abcdefghijklmnopqrstu 7× 7 = 7abcdefghijklmnopqrstu.

Monks play chess.

There was a monk in ancient India who was very proficient in chess, and the king happened to like playing chess. One day, the king called the monk to his palace to play games with him. The king said to him, "I heard that you are good at playing chess, so I invited you to play chess with me." Don't dare to hit me just because I am the king, you should show your real skill. If you beat me, I can promise you anything. The monk said, "Since your Majesty allows me, I dare to play a few games with your Majesty. But if I beat you, I only have one small request. " The king said, "as I said just now, you can make any conditions, and I will meet your requirements." The monk said, "My request is very simple. Isn't there 64 squares on this chessboard? I win you a set, you give me the first box of one grain of rice, win two sets, give me the second box of two grains of rice, win three sets, give me four grains of rice, give me four sets of eight grains of rice, ... each set is twice as big as the last set until this sixty-fourth box. " The king smiled and said, "It's not easy. There is a lot of rice in our national treasury, even less than nine Niu Yi hairs. " Monk Gao Kun said, "Your Majesty, don't go back on your word." The king said, "It's a deal." So they played a game of chess. As a result, the monk won 30 sets Guess how many meters the king should give the monk? "

Han Xin ordered the soldiers.

Han Xin was a famous general of Han Dynasty in China. He once commanded thousands of troops and knew the number of his soldiers like the back of his hand. He had a unique method of counting soldiers, which was later called "Han Xin Point Soldiers". His method is as follows: after the troops were assembled, he asked the soldiers to report 1, 2, 3- 1, 2, 3, 4, 5- 1, 2, 3, 4, 5, 6, 7 three times, and then reported the remainder of each time to him to let him know the troops. His calculation methods are also called "ghost valley calculation", "partition calculation" and "pipe cutting" in history, while foreigners call it "Chinese remainder theorem". Someone summed up the solution to this problem with a poem: seventy-three people walk together, five trees and twenty-one branches, and seven children reunite in the middle of the month, except for 105. This means that the first remainder is multiplied by 70, the second by 2 1 and the third by 15. Add up the results of these three operations and divide by 105, and the inexhaustible remainder is the number (that is, the total). For example, if three 3-site reports are 1, five 5-site reports are 2, and seven 7-site reports are 3, the total is 52. The formula is as follows:

1×70+2×2 1+3× 15= 157

157÷ 105= 1……52

Here is a question for the students. Please use the "Han Xin's Point Troop Method" to calculate.

Xiaohong helped Aunt Zhang release ducks in the summer vacation, but she always couldn't count how many. She counted three first, and there were three left. She counted five more, leaving only four. She counted seven more, leaving only six. She still can't figure out how many ducks are in a * * *. Children, please help Xiaohong figure out how many ducks Aunt Zhang Er has fed.

Strange numbers

The math teacher asked his students, "will there be such a six-digit number?" Multiply it by 1, 2, 3, 4, 5, 6, and the product of six digits is the same, but the arrangement order is slightly different? "

Will there be such a strange number? The students find it hard to believe.

"yes. There are six such figures. Now I'll write it down. Multiply yourself by 1-6 and look at these six interesting products. This is a very interesting thing. " The math teacher has finished.

Write six numbers on the blackboard.

Son, you must want to know that six-digit number, right?

Interesting natural number

The sum of five consecutive natural numbers is 350. What are these five natural numbers?

Buy groceries

Xiaohei came back from the vegetable market and told his father that he had bought four dishes: four cucumbers, three tomatoes, six potatoes and five peppers. "Cucumber is 6 cents each and pepper is 9 cents each," Xiaohe said to his father. "A * * * spent 1 yuan 70 cents."

"This account is wrong," Dad said with a smile. There must be a calculation error. "

"You don't know how much potatoes and tomatoes are worth, so how do you know you are wrong?"

"Do it again, you must be mistaken." Dad said positively.

Xiaohe calculated it carefully and it was really wrong. Strange, how did dad know?

Bottom hole bug?

A bug accidentally fell into the well. It's climbing every day. Unfortunately, it can climb 3 meters every day and slide down 2 meters at night. But the bug insisted on climbing. This well is 20 meters from the bottom to the wellhead. Insects began to climb up from the bottom of the well in the early morning. How many days will it take to climb out of the wellhead?

A few nines

Both Mingming and Shen like math very much. One day, Mingming asked Shen, "What do you like best?"

"I like 9 best."

"From 1 to 100, how many times did you say' 9'?"

"ah! ..... this is "difficult", "this is to be counted clearly"

"One minute" clearly means.

Children, please tell me how many 9s there are from 1 to 100 in one minute.

Zheng Banqiao drinks.

Zheng Banqiao, a painter and calligrapher in Qing Dynasty, was a county magistrate in Weixian County, Shandong Province. One spring, he was walking in the street with a pot of wine, reciting poems and painting. He happened to meet his old friend Yoshiyama, who said, "Didn't you invite me to drink alone?" Zheng Banqiao said, "Please, I'd love to, but you're late. I'm out of wine. " Lushan asked, "How much wine did you drink alone?" Zheng Banqiao smiled and sang a poem: "I have a pot of wine to carry along the street. Double my poem and draw a picture. Write poems and draw pictures, and drink all the wine in the pot. How much wine do you think is in my pot? " Jishan blinked for a long time and said, "I calculated that there are seven or eight glasses of wine in your pot." Zheng Banqiao said, "Yes, you are very clever." Children, do you know how to calculate the mountain map?

Einstein's Mathematical Games

The great scientist Einstein was very clever when he was a child. Once his classmates played together, he said, "How about we play a math game?" The student said, "How? Einstein said, "As long as you think of a number and then do some calculations, I can know what the number you think of at first?" Tom said, "I don't believe it, but I can try." Einstein said, "Well, let's start now. Just think of a number in your heart. " "I think it over." Tom said to add 18 to this number. "

"Add 136."

"Subtract 27."

"Subtract what you think."

Tom did the calculation according to Einstein's request. Before he could tell the answer, Einstein said, "The last number is 254."

Tom was shocked. Einstein is absolutely right, but how did he work it out?

Mathematics on the wall clock

On Sunday afternoon, Xiao Lin began to do his homework at home. When he started to do the first question, the wall clock on the wall just struck four. After finishing his Chinese and math homework, Kobayashi looked at the wall clock again. The long and short hands of the clock just overlap to form a straight line. Can you work out how long it took Xiao Lin to do his homework?

Xiao Lin went to play in the street after finishing his homework. After playing for a while, he suddenly remembered that there was still a composition to write, so he hurried home to write it. Xiao Lin looked at his watch when he began to write his composition. It's just five o'clock. He looked at his watch when he finished writing the first paragraph. At this time, the long needle and the short needle walked at right angles. He continued to write, and when he finished, the hour hand and the minute hand of the clock eye just walked at right angles. How long did it take Xiao Lin to write the first paragraph? How long did it take to write an article?

Divide wine

Zhang San and Li Si each took a wine bottle, which contained wine. They want to divide the wine equally. Li Si first poured the wine from his own bottle into Zhang San's bottle, which doubled the wine in Zhang San's bottle, and then poured Zhang San's wine into Li Si's bottle, which tripled the wine in Li Si's bottle. I poured it twice, but it was still uneven. There is wine160g in Zhang San bottle and wine120g in Li Si bottle. Excuse me, how much wine is there in Zhang San and Li Si's bottle?

Is there such a score?

In math class, the teacher said to the students, "Can you find five scores less than 1/3 and greater than 1/4?" Zhang Shan thought for a long time and said, "I can't find such a person." At this time, Liu Xiaojuan raised his hand and said, "I found it." The teacher said, "Liu Xiaojuan is very clever." Students, do you know what numbers Liu Xiaojuan found?

The monk counted the beads.

Xiaoming and Xiaoguang go to the temple to play. When they see monks meditating, they always count the beads in their hands one by one. Xiao Ming said, "How many can you count in a minute?" Xiaoguang looked at it for a while and said, "I think it can count to 200." Xiao Ming added, "If it is 1 trillion, I think it will take several days, eight days and eight nights at most." Xiaoguang said, "1 trillion is 1 trillion, right?" Xiao Ming said, "Yes." Xiaoguang said: "In that case, I don't think I can count 1 trillion in my life." Xiao Ming said, "Impossible, you speak too long." Children, how long do you think it will take to count to one trillion?

Cattle grazing

This question was put forward by the great scientist Newton. Seemingly simple, in fact, it needs to be solved with brains. The problem is this: there is a pasture with 27 cows, and the grass is eaten in 6 days; If you raise 23 cows, you will eat up the grass in 9 days; If you have 2 1 cow, how many days can you finish the grass on the farm? Please note that the grass on the pasture is constantly growing, not fixed.

Computational problems in early history

Archaeologists found a prehistoric mural in Spain, which drew some figures of human figures and wild animals, and also drew some puzzling calculation problems, which were also Arabic numerals, but archaeologists couldn't figure out these calculation problems after reading it for a long time. Later, they realized that these calculated figures are not quite the same as our current figures, but they definitely conform to the four algorithms. Children, please look at these formulas carefully, think about what the numbers in the formulas are now, and then translate them.

5+6+7=5×6×7

5+5=6

6÷5=6

7×5=7

Coin problem

One day, Fangfang, Mingming and Lili were playing together. After playing for a while, they broke out in a sweat. Fangfang said, "Let's buy sorbet to eat." As he spoke, he took out a handful of coins from his pocket. At first glance, they were all nickels. Yan Mingming also took out a handful of coins from his pocket, all of which were 2 cents, and also took out a force, all of which were 1 cent. Three people put the money together and counted it. One * * * is 1 yuan.

"How much money did each of us bring?" Li Li asked.

"I can't remember." Fangfang said, "I only remember that my coin was twice as big as Mingming's."

"I have exactly twice as many coins as I do." Clearly said.

"Let's share a flower." Fangfang grabbed the coin and went to buy sorbet.

Lily is thinking, how much money did each of us bring?

Card problem

On Sunday, Linlin went to Sensen's house and saw Sensen fiddling with five cards on the table. These five cards

The film says 4, 5, 6,+and = respectively.

Lin Lin asked, "What are you wearing?"

Sensen said, "I want to put these five cards together into an equation."

Lin Lin said, "Isn't it easy?"

He set it up as soon as he said it, but he couldn't set it up for a long time. 4+5, 4+6 and 5+6 all exceed the maximum number, and 6, 6-5 and 6-4 are not enough for the minimum number 4.

"This is impossible. This equation will never hold. " Lin Lin said.

"You can put it in." Sensen said, and put a formula on the table. It was an equation.

Little friend, do you know what Sensen said?

When shall we meet?

Obana and MengMeng quarreled over a trivial matter, and neither of them spoke to anyone. The monitor Xiaohong wanted to ask the two of them to talk together, but no one went. This really worries Xiaohong. What can we do to keep them together? It suddenly occurred to her that everyone in Obana and MengMeng has the habit of running in the morning, and they are all on the path next to the campus. It's 6 o'clock in the morning, but Xiaohua comes every three days and MengMeng comes every five days. Today is 654381October 3rd. Both Obana and MengMeng went this morning. Xiaohong knows that MengMeng will leave tomorrow, so when can we meet next time? Xiaohong calculated the time when they met and went that morning, so she met them both at the same time. She called them together and told them the truth of unity. They all realized that there was something wrong with their practices and made self-criticism. From then on, they became good friends. Children, can you guess the date when Obana MengMeng met on the path?

Galileo's mathematical problems

Galileo is a famous scientist in Italy. Once he went to the racecourse to watch horse races and came up with a math problem. Here's the question. There is a 600-meter-long happy track at the racecourse. Now there are three horses, A, B and C. A can run 2 laps a minute, Otsuichi can run 3 laps a minute and C can run 4 laps a minute. If these straight horses run side by side on the same starting line and in the same direction, how many minutes will it take for these three horses to get back on the starting line?

Clever trade-off

Mr. Zhao, Mr. Qian and Mr. Sun all weigh about 60 Jin, but I don't know the exact figure. Now there is only 100 kg weight and weighbridge. Is there any way to weigh them?

Skillfully measure the height of the pyramid

The pyramids are famous Egyptian buildings, especially pyramid of khufu. The entire pyramid used 2.3 million stones, and it took 65,438+10,000 slaves 30 years to build this building. After the completion of the pyramid, the king asked another question, how high is the pyramid? No one can answer this question. The king was furious and threw all the scholars who couldn't answer into the Nile. When the king tried to kill another scholar, the famous scholar tallis appeared and ordered the executioner to stop. The king said, "Can you know the height of the pyramid?" Tallis said, "Yes, Your Majesty." The king said, "Then how high is it?" Tallis calmly replied: "147 meters." The king asked, "Don't talk nonsense. How did you measure it? " Tallis said, "I can show it to you tomorrow."

The next day, when the sun was shining, tallis came to the bottom of the pyramid with only a stick. King Qi sneered, "You want to cheat me with this broken stick? If you can't measure it today, you will be thrown into the Nile! " Tallis replied unhurriedly, "If I can't measure it, it's not too late for your majesty to throw me into the Nile."

Then, tallis began to measure, and finally, the king had to accept that his measurement was reasonable.

Children, do you know how to measure in tallis?

How many chickens and dogs are there?

Chickens and puppies walk on the ground of 79 feet and 200 feet. Think about it and count it. How many chickens are there? How many dogs?

How many monks, big and small?

This is an old math problem: there are hundreds of monks, four for each big monk and one for each little monk. How many monks, big and small?

Too many, give me extra points!