Goals:
develop interest in mathematics, logic and ingenuity, the ability to prove and explain; communicative competence.
Preparation for the lesson:
tasks for mathematical combat are written down on album sheets in triplicate: for the teams and the teacher.
Progress of the lesson:
- Two teams participate in a mathematical battle. Each team has a captain, who is determined by the team before the start of the battle. The battle consists of two stages. The first stage is solving problems, the second is the battle itself. During the first stage, problem solving can occur jointly with the whole team. Remember that none of the participants in the battle can go to the board more than twice. Therefore, a participant who has solved many problems that others have not solved must, during the first stage, tell his teammates the solutions he received.
- The second stage begins with a captain's competition. By decision of the team, any member of the team can participate in the competition instead of the captain. The winning team decides which team makes the first call. This, as well as all other decisions of the team, is announced by the captain.
Captains competition:
A super-blitz is held on three questions, the captain who scores two or three points wins. The captain can earn a point by answering the question correctly. The first person to answer is the one who raises the signal card (prepared in advance) or hand faster.
- A chocolate costs 10 rubles and another half a chocolate bar. How much does a chocolate bar cost?
- Hares are sawing a log. They made 10 cuts, how many logs did they get?
- How much earth is in a hole 2 m deep, 2 m wide, 2 m long?
Answers: 20 rubles; 11 logs; not at all.
- The call is made as follows. The captain announces: “We challenge our opponents to task number...”. The other team may or may not accept the challenge. The team that accepted the challenge puts up speaker, the other team - opponent. After a meeting with the teams, the captains name the opponent and the speaker. The speaker’s task is to give a clear and understandable solution to the problem. The opponent’s task is to find errors in the report. During the report, the opponent has no right to object to the speaker, but may ask him to repeat an unclear point. The main task of the opponent is to notice all the dubious places and not forget about them until the end of the report. At the end of the report, a discussion takes place between the speaker and the opponent , during which the opponent asks questions about all the unclear parts of the report. The discussion ends with the opponent’s conclusion: “I agree with the decision” or “I believe that there is no solution, since such and such was not explained.”
- After this, the jury (teacher) awards points according to following rules. Each task costs a different number of points, as they differ in difficulty level. First and second problems – 6 points. Third, fourth, fifth and sixth – 8 points. Seventh and eighth – 10 points. Ninth and tenth – 12 points. In case of an absolutely correct decision, the speaker's team receives all these points. For errors and inaccuracies, points will be deducted. The number of points deducted is determined by the proximity of the story told to the right decision. If errors were found by the opponent, then the opposing team receives up to half of the points deducted. Otherwise, all selected points go to the jury. If the jury decides that the report does not contain a solution to the problem, then the opposing team has the right to tell the correct solution. At the same time, to the points scored for opposing, she can add points for telling the solution to the problem. The team that makes an incorrect report nominates an opponent and can earn points by opposing.
- The team receiving the call may refuse to report. In this case, the calling team must prove that it has a solution to the problem. To do this, she nominates a speaker, and the second team nominates an opponent. If there is no solution and this is proven by the opposing team, then they receive half the points for this problem, and the challenging team must repeat the challenge. This procedure is called checking the correctness of the call. In all other cases, calls alternate.
- During the bout, each team is entitled to six 30-second breaks. Breaks are made in cases where there is a need to help a student standing at the blackboard or replace him. The decision to take a break is made by the captain.
- A team that has received the right to a challenge may refuse it. In this case, until the end of the battle, only their opponents have the right to report, and the team that refused can only oppose. Opposition is carried out according to the usual rules.
- At the end of the battle, the jury counts the points and determines the winning team. If the gap in the number of points does not exceed 3 points, then the battle is recorded as a draw.
- A team may be fined up to 6 points for noise, rudeness towards an opponent, failure to comply with the requirements of the jury, etc.
Tasks for conducting a mathematical battle among 6-7 grades.
Round 1 (warm-up)
1. A car drove for 3 hours at a speed of 60 km per hour and for 7 hours at a speed of 80 km per hour. Find average speed car?
2. Half of half is equal to half. Find this number?
3. The mass of 5 apples and 3 pears is the same as the mass of 4 of the same apples and 4 of the same pears. What is easier: apples or pears?
4. 5 workers will produce 5 parts in 5 days. How many parts will 10 workers produce in 10 days?
5. Vovochka collected beetles and spiders in a box - 8 in total. How many spiders are there in a box if there are 54 legs in total?
Round 2 (tasks on weighing and transfusion)
1. Among the 80 coins, there is one counterfeit. Find it in four weighings on cup scales without weights, if it is known that it is lighter than the real thing?
2. How to divide 8 liters of milk equally if the milk is in an 8-liter can and there are two empty cans 3l and 5l?
3. There are two hourglass: for 7 minutes and for 11 minutes. The porridge should be cooked for 15 minutes. How to cook it by turning the clock over the minimum number of times?
Round 3 (movement problems)
1. Two motorists simultaneously left points A and B towards each other. After 7 hours, a distance of 136 km remained between them. Find the distance between A and B if one can travel the entire distance in 10 hours, and the other in 12 hours.
2. Having passed half the way, the boat increased its speed by 25% and therefore arrived half an hour earlier. How long did it take him to move?
4th round (captains competition)
Three certain wise men entered into an argument: which of the three is wiser? The dispute was resolved by a random passer-by who offered them a test of intelligence.
“You see,” he said, “I have five caps: three black and two white. Close your eyes."
With these words, he put a black cap on each of them, and hid two white ones in bags.
“You can open your eyes,” said the passer-by. “Whoever guesses what color decorates his head has the right to consider himself the wisest.”
The wise men sat for a long time, looking at each other... Finally, one exclaimed.
“I’m wearing black!”
How did he guess?
tasks for conducting a “mathematical battle”
among 6-7 grades.
Rules of the game:
Math fight- competition between two teams in solving problems. Teams receive task conditions and a certain time to solve them. When teams are solving problems, any significant explanation of the problems given by one of the teams must be in shortest time communicated to all teams. After the allotted time has passed, the battle itself begins, when the teams explain to each other the solutions to the problems in accordance with the rules.
If one of the teams tells the solution, then the other acts as an opponent, i.e. looks for errors (shortcomings) in it. The speeches of the opponent and the speaker are assessed in points. If the teams, after discussing the proposed solution, did not solve the problem to the end or did not find an error, then the jury can take part of the points. The winner of the battle is the team that ultimately scores more points.
Purpose of the game:
Developing interest in solving complex mathematical problems, ability to work in a team, preparation for participation in city Olympiads.
Analysis of the game:
The “mathematical battle” was held as part of the week of Mathematics among 6G (mathematics) and 7A (gymnasium). The game took place in a friendly atmosphere. Ingenuity tasks were specially selected that the children could solve, regardless of the material being studied. The meeting ended with a victory for grade 7, with a slight margin of 2 points. But this did not upset the 6th grade. on the contrary, they sensed their capabilities and demand revenge. The goal that I set for myself: to arouse interest in solving problems and to feel self-confidence was achieved.
Rules of mathematical combat
1. Order of battle. Math fight is a competition between two teams in solving mathematical problems. It consists of two parts. First, teams receive task conditions and a certain time to solve them. When solving problems, the team can use any printed literature, non-programmable calculators, but has no right to communicate with anyone except the jury. Also, teams do not have the right to use the Internet, any electronic media or mobile phones. After this time, the actual battle begins, when the teams tell each other the solutions to the problems.
2. Start of the battle. The fight starts with captains competition. The captain who first solved the proposed task raises his hand and presents the answer. If his answer is correct, he wins, if incorrect, his opponent wins, and he is not required to submit his answer. The winning team in the captain's competition decides whether it wants to challenge the opposing team to a report in the first round or be called.
3. Order of battle. The fight consists of several rounds. At the beginning of each round, one of the teams challenges the other team to one of the problems whose solutions have not yet been revealed. The calling command may also refuse further calls (§ 11). The called command can accept the challenge (§ 4) or perform a validation check (§ 9).
The team that made the challenge in the current round becomes challenged in the next round, except in the case of an incorrect challenge (§ 10), when it is forced to repeat the challenge in the next round.
4. Accepted call. If the challenge is accepted, the called team sets up a speaker, the calling team sets up an opponent. A team wishing to preserve access to the board (§ 13) may refuse to field an opponent. Then she does not participate in this round. The speaker, with the permission of the jury, can take with him a paper with drawings and calculations. But he has no right to take the text of the decision with him. The speaker tells the solution to the problem; the opponent, by agreement with the speaker, asks him questions either during the presentation or after the report. All calculations are usually carried out by the presenter on the board and without the use of a calculator. No more than 15 minutes are allotted for the report, and no more than 15 minutes for the subsequent discussion between the opponent and the speaker.
5. Rights of the speaker and opponent.
During the report, the opponent can: ask questions to the speaker with his consent; ask the speaker to repeat any part of the report; allow the speaker not to prove any facts that are obvious from the opponent’s point of view.
During the discussion, the speaker can: ask the opponent to clarify the question; refuse to answer your opponent’s question, citing the fact that (a) he does not have an answer, (b) he has already answered this question, (c) the question, in his opinion, is not relevant to the task.
During the discussion, the opponent can: ask the speaker to repeat any part of the report; ask the speaker to clarify any of his statements; ask the speaker to prove the formulated non-obvious and not generally known statement (facts included in the school mathematics course are usually considered generally known).
The speaker is not obliged to: state the method of obtaining the answer if he can prove the correctness and completeness of the answer in another way; compare your solution method with other possible methods.
6.Opponent's conclusion. When the questions are asked and answered, the opponent makes a conclusion in one of three forms: (a) “I completely agree with the decision”; (b) “The solution is basically correct, but it has the following shortcomings...”; (c) “The solution is incorrect, the fundamental error is as follows...” The opponent should remember that the jury ultimately evaluates not his questions, but his conclusion, which must be motivated!
A conclusion on an incorrect decision can be made in the form: “The decision is incorrect, I have a counterexample.” In this case, the jury asks the opponent to present a counterexample in writing, without revealing it to the speaker. If the jury accepts the counterexample, the speaker is given a minute to attempt to correct the decision. Similar actions are carried out based on the opponent’s statement “The solution is incomplete, not all cases have been considered.”
If the opponent agrees with the decision, he and his team no longer participate in this round; Then the jury asks questions to the speaker. Until the speaker's decision has been refuted, the opponent has no right to tell his solution, even if it is much simpler.
7. Accrual of points. In each round, 12 points are awarded, which are distributed between the presenter, opponent and jury. The speaker receives 12 points for an error-free solution. Otherwise, the jury deducts points from the speaker for holes contained in the solution. Each hole is worth an even number of points. If the speaker fills a hole after an opponent’s question asked before the end of the report, points are not deducted from the speaker. If the speaker repairs the hole after the opponent's question asked at the end of the report, the cost of the hole is divided equally between the opponent and the speaker. If the presenter fails to repair the hole, the opponent immediately receives half of its value. If the opponent did not notice the hole, and the jury pointed it out with their questions after making a conclusion, the jury receives half of the cost of the hole, and the other half goes to the speaker or the jury, depending on whether the speaker was able to repair the hole or not.
8. Role reversal. Having made a preliminary assessment of points, the jury asks the opponent if he would like to present a complete solution to the problem in the case where the opponent has proven that the speaker does not have one, or to fill in the remaining holes. If the opponent agrees to a partial or complete change of roles, he temporarily becomes the speaker and tries to earn the second half of the value of the holes he discovered. The former speaker, when opposing, can himself score half the points that the former opponent is trying to earn as a speaker. Secondary role changes cannot be made.
9. Validation check is that the called command refuses to tell the solution to the problem, but instead checks whether the calling command has solved it. In this case, the calling team sets up a speaker, and the called team sets up an opponent. If the calling team immediately admits that it does not have a solution, then the calling team receives 6 points. In this case, the speaker and opponent are not assigned and exits to the board are not counted. When checking for correctness, roles cannot be changed. If, during the correctness check, the opponent proves that the speaker does not have a solution, then he receives at least 4 points.
10. The order of the next call when checking for correctness And. If the call is recognized as correct (the calling team presented a solution, or the opponent could not prove that the presenter does not have a solution), then the called team makes the next call. If the call is recognized as incorrect (the calling team immediately admitted that it does not have a solution, or the opponent was able to prove that the presenter does not have a solution), then the next call is made again by the calling team.
11. Call Rejection. Starting from a certain round, one of the teams may refuse further challenges. In this case, opponents can nominate speakers for any previously unconsidered tasks, and the team that refuses the challenge nominates opponents. Once calls are rejected, roles can no longer be changed.
12. Time-out. Communication between the speaker and the team is allowed only during the 30-second break taken by the team. At this time, opponents can also deliberate, using up all 30 seconds of the break. A team may take no more than six 30-second breaks per bout. If the opponent begins to make a conclusion, his team can recall the opponent’s words within 10 seconds and take a time-out. If after the opponent’s conclusion there is no recall within 10 seconds, then the opponent’s conclusion is considered made and cannot be changed.
13. Number of exits to the board. Each player is allowed to come to the board (whether as an opponent or as a speaker) no more than twice per battle, regardless of the number of team members participating in this battle. If desired, the team may not field an opponent for the round, thereby saving the number of exits.
14. Replacement order. A team can change its speaker at any time, which is equivalent to using two breaks. When replacing, the exit is credited to both participants.
15. 10 minute breaks. Team captains have the right to ask the jury for a 10-minute break during the fight (approximately every two hours). A break may only be granted between rounds. In this case, the calling team, before the start of the break, makes a challenge in writing and submits it to the jury, who announces the call after the end of the break.
16. End of the fight. The battle ends when all problems have been considered or when one of the teams refused the challenge and the other team refused to tell the solutions to the remaining problems.
17. Determination of the winner. The team with the most points is considered the winner of the battle. If the difference is no more than 3 points, the battle is considered to end in a draw (except for specially specified cases).
18. General rules behavior I. During the battle, the team communicates with the jury only through the captain; if the captain is at the board - through his deputy. The speaker and opponent address each other only in a respectful manner, using the “you” form. If these rules are violated, the team is first warned and then penalized.
19.Jury. The jury is the supreme interpreter of the rules of combat. The decisions of the jury are binding on the teams. The jury can withdraw the opponent's question, stop the report or opposition if they are delayed. The jury keeps a record of the fight on the board. If one of the teams does not agree with the decision made by the jury on the task, it has the right to immediately demand an analysis of the situation with the participation of the league leader. Once the next round starts, the score of the previous round cannot be changed.
Math fight
Math fightis a competition between two teams in solving mathematical problems.
Matboy is a developing form of extracurricular work in mathematics. She has actively entered into the practice of the school in the last 10-15 years.
Matboys can be organized as tournaments intraclass , school-wide, or as city or district ones, when national teams of schools or districts compete.
Matboys are always held in the form of competitions, the results of which are assessed by a jury. Mathboys are a very exciting and emotional form of mathematical competition; teams should always feel the support of their fans. Tasks in matboys can be designed to be completed within a certain period of time; sometimes the team is given a week to complete the task. However, matboys with express tasks are especially interesting, which are completed in a matter of minutes and are immediately assessed by the jury.
The experience of mathboys will help participants in the future: the ability to make a scientific report, listen and understand the work of another, ask clear, substantive questions - all this will be useful at seminars and conferences, for reviewing books and articles, and for joint scientific work. And one more thing: students from different schools get to know each other at matboys and create a new circle of friends. And the last thing: after a successful matfight, the taste for good work awakens, you want to perform again, but properly, taking into account all the mistakes. Therefore, losing to teams is sometimes more useful than winning.
Matboys originated in Leningrad and were invented by Joseph Yakovlevich Verebeychik around 1965. The first matboys were held within the walls of school No. 30, where Joseph Yakovlevich worked as a mathematics teacher and led clubs. Many years later, matboys began to be held in different cities, but some discrepancies in the rules arose. With great difficulty, thanks to summer mathematical schools in Kirov, where Moscow, Leningrad and Kirov teachers met, these differences were overcome in long disputes.
Signs:
Availability of rules of communication in competition conditions;
Availability common goal teams;
Limited time and its distribution across the stages of the competition;
Objectivity in assessing results;
Clear organization system;
Entertaining formulation of assignments and tasks.
Characteristic:
Target:
- Development of cognitive interest in the subject.
- Generalization and systematization of knowledge: Mathboy uses tasks mainly involving logic and ingenuity. As well as tasks on the topics: drawing up equations and solving them; Polynomials and arithmetic operations on them; Solving systems of equations with two unknowns.
- Developing the ability of group members to interact with each other.
- Dial greatest number points.
Preparation for the lesson:
Problems for mathematical combat are written down on album sheets in four copies: for the teams, the jury and the teacher. Fight report for the jury. Black box “with a surprise” (see captain competition)
Rules:
Two teams (7 people each) participate in a mathematical battle. Each team has a captain, who is determined by the team before the start of the battle. The battle consists of two stages.
The first stage is solving problems, the second is the battle itself. During the first stage, problem solving can occur jointly with the whole team. Remember that none of the participants in the battle can go to the board more than twice. Therefore, a participant who has solved many problems that others have not solved must, during the first stage, tell his teammates the solutions he received.
The second stage begins with a captain's competition. (By decision of the team, any member of the team can participate in the competition instead of the captain). The winning team decides which team makes the first call. This, as well as all other decisions of the team, is announced by the captain.
▪ The call is made as follows. The captain announces:. The other team may or may not accept the challenge. The team that accepted the challenge nominates a speaker, the other team nominates an opponent. After a meeting with the teams, the captains name the opponent and the speaker. The speaker’s task is to provide a clear and understandable solution to the problem. The opponent’s task is to find errors in the report. During the report, the opponent has no right to object to the speaker, but may ask him to repeat an unclear point. The main task of the opponent is to notice all the dubious places and not forget about them until the end of the report. At the end of the report, a discussion takes place between the speaker and the opponent, during which the opponent asks questions about all the unclear parts of the report. The discussion ends with the opponent’s conclusion: “I agree with the decision (“disagree”", explanation).
▪ After this, the jury (teacher) awards points. Each task is worth 12 points. For errors and inaccuracies, points will be deducted. The number of points deducted is determined by the proximity of the story told to the correct solution. If errors were found by the opponent, then the opposing team receives up to half of the points deducted. Otherwise, all selected points go to the jury.
▪ The team receiving the call may refuse to report. In this case, the calling team must prove that it has a solution to the problem. To do this, she nominates a speaker, and the second team nominates an opponent.
▪ During the bout, each team is entitled to six 30-second breaks. Breaks are made in cases where there is a need to help a student standing at the blackboard or replace him. The decision to take a break is made by the captain.
▪ If the captain is at the board, he leaves a deputy, who at that time acts as captain. The names of the captain and deputy are communicated to the jury before the start of solving problems. When solving problems, the captain's main responsibility is to coordinate the actions of team members so that with the available forces they can solve as many problems as possible. The captain finds out in advance who will be the speaker or opponent for a particular task and determines all the team’s tactics for the upcoming battle.
▪ A team that has received the right to a challenge may refuse it. In this case, until the end of the battle, only their opponents have the right to report, and the team that refused can only oppose. Opposition is carried out according to the usual rules.
▪ The jury is the supreme interpreter of the rules of combat. In cases not provided for by the rules, it makes a decision at its own discretion. The decisions of the jury are binding on the teams.
▪ At the end of the battle, the jury counts the points and determines the winning team. If the gap in the number of points does not exceed 3 points, then the battle is recorded as a draw.
▪ A team may be penalized up to 6 points for noise, rudeness towards an opponent, etc.
Protocol of Mathematical Combat
Call no. | Task No. | Who called whom? | Jury |
|||||
Surname | Number of points. | Surname | Number of points. | Number of points. | Notes, not accurate |
|||
Total: |
Sample:
Call no. | Task No. | Team name | Who called whom? | Team name II | Jury |
|||
Surname | Number of points. | Surname | Number of points. | Number of points. | Notes, not accurate |
|||
Team I broke the silence |
||||||||
What class is the math battle designed for?
Math battle for 7th grade
Progress of the competition: Epigraph: “The subject of mathematics is so serious that it is useful not to miss
chance to make it entertaining»
(Pascal)
I invite two teams to conduct the battle: the “team name” team and the “team name” team.
(To teams) Please receive your assignments. Within 15-30 minutes you should complete it.
Now let's start the math battle. I call the team captains.
"Captains Competition"
Assignment: You need to guess what is in the black box, using as few clues as possible.
Tips:
- The oldest of these objects lay in the ground for 2000 years.
- Under the ashes of Pompeii, archaeologists discovered many such objects made of bronze. In our country, this was first discovered during excavations in Nizhny Novgorod.
- For many hundreds of years, the design of this item has not changed, it was so perfect.
- In Ancient Greece, the ability to use this object was considered the height of perfection, and the ability to solve problems with its help was a sign of a high position in society and a great mind.
- This item is indispensable in architecture and construction.
- Necessary for transferring dimensions from one drawing to another, for constructing equal angles.
- Riddle: “Two legs conspired
Make arcs and circles"
Additional competition for captains:Who can name 5 mathematical terms starting with the letter “P” faster:
- Unit of measurement of angles.
- A segment in a circle.
- Type of number.
- Flat quadrilateral.
- Equations that have the same solutions.
The captain of the team "team name" won.
Over to you, captain. (“We challenge our opponents to task number...”.)
Team "team name", do you accept the challenge? (Yes)
What questions or additions will the jury have?
Dear jury, please add your ratings to the battle report.
The floor is given to the team "team name"
Team "team name", do you accept the challenge?
Please nominate a speaker and an opponent.
While our esteemed jury is counting the results, I invite the teams to the stage...
To sum up the results of the mathematical battle, the floor is presented to the chairman of the jury...
So, in today's mathematical battle the team "team name" won with the score: ...
The team "team name" is assigned a title"The wisest of the wise",
Team "team name" -"The smartest of the smartest."
Thanks to the teams, please take your seats.
List of TASKS
- A chocolate costs 10 rubles and another half chocolate. How much does a chocolate bar cost?
- The man says: "I lived 44 years, 44 months, 44 weeks and 44 days" How old is he?
- The car meter showed 12921 km. After 2 hours, a number again appeared on the counter that read the same in both directions. At what speed was the car traveling?
- Letter notation was first introduced by the French mathematician François Viète (1540-1603). Before this, they used cumbersome verbal formulations. Try to write down the following example in modern symbolism: “The square and the number 21 are equal to 10 roots. Find roots».
- How old is grandma?
Vasya came to his friend Kolya.
Why weren't you with us yesterday? – asked Kolya. – After all, yesterday my grandmother celebrated her birthday.
“I didn’t know,” said Vasya. - How old is your grandmother?
Kolya answered intricately: “My grandmother says that there has never been a time in her life when her birthday was missed. Yesterday she celebrated this day for the fifteenth time. So figure out how old my grandmother is.”
- Let’s say I took 100 rubles from my mother. I went to the store and lost them. Met a friend. I took 50 rubles from her. I bought 2 chocolates for 10 each. I have 30 rubles left. I gave them to my mother. And I still owe 70. And my friend owes 50. Total is 120. Plus I have 2 chocolates. Total 140! Where are 10 rubles?
- Three friends: Ivan, Peter and Alexey came to the market with their wives: Maria, Ekaterina and Anna. We don't know who is married to whom. You need to find out this based on the following data: each of these six people paid for each item purchased as many rubles as the number of items he bought. Each man spent 48 rubles. more than his wife. In addition, Ivan bought 9 items more than Catherine, and Peter bought 7 items more than Maria.
- Fill in the cells so that the sum of any three adjacent cells equals 20:
- A tourist goes on a hike from A to B and back, and completes the entire journey in 3 hours 41 minutes. The road from A to B goes first uphill, then on level ground and then downhill. How far does the road go on level ground if the tourist’s speed is 4 km/h when going uphill, 5 km/h on level ground, and 6 km/h when going down the mountain, and the distance AB is 9 km?
- The number ends with the number 9. If you discard that number and add the first number to the resulting number, you get 306,216. Find this number.
Answers:
Captains competition: Compass
Additional competition for captains:radian, radius, rational, rhombus, equivalent.
Problem solutions:
- Answer: 20 rub. . X/2+10=X, where X is the price of a chocolate bar.
- Answer: 48 years old 44 months = 3 years and 8 months.
44 weeks = 9 months
44 days = 1.5 months.
44 years + 3 years and 8 months. + 9 months + 1.5 months = 48 years and 6.5 months.
- Answer: 55 km/h (105 km/h).
13031-12921=110 (km)
110:2 = 55 (km/h)
or
13131-12921=210 (km)
210:2=105 (km)
- Grandmother is 60 years old , she was born on February 29th. Thus, she celebrated her birthday once every 4 years.
- You need to add not chocolates, but 30 rubles that you gave away. Chocolates no longer count, because... 30 rub. have already paid, the remaining 20 went towards the debt.
Borrowed: 100+50=150 rubles.
Should: 150-30=120 rub.
Spending 100+20=120
After all the losses and expenses, 150-120 = 30 remained - I gave them to my mother, and I still owe her 70 rubles. and 50 for a friend, a total of 120 rubles. (compare with the 2nd line).
If his wife bought at items, then she paidrub. So we have, or (x-y)(x+y)=48. Numbers x,y– positive. This is possible when x-y and x+y are even, and x+y>x-y.
Expanding 48 into factors, we get: 48=2*24=4*12=6*8 or
Solving these equations, we get:
Looking for those meanings x and y , the difference of which is 9, we find that Ivan bought 13 items, Catherine – 4. In the same way, Peter bought 8 items, Maria – 1.
Thus, we get pairs:
- The numbers between which there are two cells must match.
The only difference is the third number: 4
Answer:
- Let x be the length of the path on level ground SD, then AC+DV=9-x.
The tourist passes sections AC and DV twice, once uphill at a speed of 4 km/h, the other
once downhill at a speed of 6 km/h.
On this path he will spend
The path on level ground will takeBecause the entire journey there and back will take the tourist 3 hours. 41 min., then
|*60
15(9-x)+10(9-x)+12*2x=221
135-15x+90-10x+24x=221
X=-4
Answer: x = 4 km.
- Answer: 278 379
Tasks for fans:
Riddles:
I don't look like a nickel
Doesn't look like a ruble.
I'm round, but I'm not a fool,
With a hole, but not a donut.
(zero)
I am neither an oval nor a circle,
I am a friend to the triangle
I am the brother of the rectangle,
After all, my name is...
(square)
The squirrel dried mushrooms,
There were 25 whites,
Yes, even 5 oils,
7 milk mushrooms and 2 chanterelles,
Very red-haired sisters.
Who has the answer?
How many mushrooms were there?
(39)
- Hares are sawing a log. They made 10 cuts. How many logs did you get? (11)
- What did the word "darkness" mean in mathematics? (many)
- Zero's rival? (cross)
- How many kids did a goat with many children have? (7)
- Triangular scarf? (kerchief)
- Who changes clothes 4 times a year? (Earth)
- An endangered breed of student? (excellent students)
Exercise: Name mathematical terms starting with the letter P:
- Hundredth of a number (percentage)
- Graph of a quadratic function (parabola)
- Relative position of two lines (parallel)
- Sum of the lengths of all sides of a polygon (perimeter)
- A segment forming a right angle with a given line (perpendicular)
- Sign to indicate action (plus)
- Geometric transformation (rotation)
- Flat quadrilateral (parallelogram)
Crossword
Horizontal:
1. A ray dividing an angle in half. 4. Triangle element. 5, 6, 7. Types of triangle (at the corners). 11. Ancient mathematician. 12. Part of a straight line. 15. 16. A segment connecting the vertex of a triangle to the middle of the opposite side.
Vertical: 2. Top of the triangle. 3. Figure in geometry. 8. Triangle element. 9. View of a triangle (sides). 10. A segment in a triangle. 13. A triangle whose two sides are equal. 14. Side of a right triangle. 17. Triangle element.
Game.
I'll tell you a story
In one and a half dozen phrases,
As soon as I say the word “three” -
Take the prize immediately!
One day we caught a pike
Gutted, and inside three
We saw small fish
And not just one, but... two.
A seasoned boy dreams
Become an Olympic champion
Look three, at the start it’s not three,
And wait for the command “one, two, ... march!”
When you want to memorize poems,
They are not crammed until late at night,
And repeat them to yourself
1. Bisector.
4. Side.
5. Rectangular.
6. Acute angular.
7. Obtuse.
11. Pythagoras.
12. Segment.
15. Hypotenuse.
16. Median.
2. Point.
3. Triangle.
8. Top.
9. Equilateral.
10. Height.
13. Isosceles.
14. Leg.
17. Angle.
When developing mathematical combat, the following was used
Literature:
- Ignatiev, E.I. In the kingdom of ingenuity [Text]. / ed. M.K. Potapov with textual processing by Yu.V. Nesterenko. – M.: Nauka, 1978. - 192 p.
The book contains entertaining problems of varying degrees of difficulty. As a rule, problems are solved using minimal information from arithmetic and geometry, but require intelligence and the ability to think logically. The book contains both problems accessible to children and problems of interest to adults.
- Magazine "Mathematics at school". – 1990. - No. 4. The article used was called "Mathematical Combat". It describes in detail what Matboy is, the rules of mathematical combat, and sample tasks.
- Karp, A.P. I give mathematics lessons [Text]: Book for teachers: From work experience. – M.: Education, 1992. – 191 p.
The Book contains methodological developments some lessons, samples of paperwork, materials for holding mathematical competitions (olympiads, matboy) and other competitions. The book will assist teachers in working with students who are interested in mathematics.
- From the book of Kovalenko V.G. Didactic games in mathematics lessons [Text]: A book for teachers. – M.: Enlightenment, 1990. – 96 p.
some tasks were taken for the relay competition.
- V.A. Gusev, A.I. Orlov, A.L. Rosenthal" extracurricular activities in mathematics in grades 6-8". M: Prosveshchenie, 1984-285 p.
- Kordemsky B.Ya. "To captivate schoolchildren with mathematics: (material for classroom and extracurricular activities). M: Prosveshchenie, 1981-112p.
This book is a kind of manual containing auxiliary materials for developing a passion for mathematics. The author has selected interesting and valuable arguments from scientists and presented original entertaining problems for mathematical games and mathematical battles.