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Fair game and reflect on the teaching process injection at the Central Primary School Dai Lifang

Teaching: Beijing Normal University under the fourth year of teaching, the seventh unit fair game (first class) P79-80.

Teaching objectives:

1, games and experience, such as the possibility of the incident and the fairness of the rules of the game, further understand the characteristics of the phenomenon of uncertainty.

2, according to life experience and experimental data to determine the rules of the game s simple fairness.

3, designed to be both fair rules of the game.

Teaching focus:

1, in-game experience is not fair.

2, in the unfair game are fair to both sides to discuss the rules of the game.

Teaching and difficult: the operational activities of experience and discussion.

Teaching preparation: the log cards, dice, coins, to pull cards, cards, balls, turntable, paper signed. (His class is divided into eight groups, each with five)

Design intent:

Fair game This class is a probability, is that students learn in the first paragraph, have attempted to describe and qualitative judgement of the incidents on the basis of the possibility, through the throwing of coins , Break- , Zhi Touzi Activities such as games, to discuss the rules of the game is fair, and personally test to verify the fairness of the rules of the game, and so on and the possibility to try to design their own so that both sides are fair game. Through this series of activities to enable students to get in the activities of intuitive feelings, experiences, such as the possibility of the incident and the fairness of the rules of the game.

The teaching process:

First, the creation of context, ask questions

1, touched the ball game division: some teachers with the ball in the box, want to touch the ball for a game Competition rules are as follows: First: his class were divided into two groups, a group of boys, a group of girls, boys and girls each a representative of touch the ball, 10, each touch, touch the ball more white girls win count, and reached Huang won the ball more balance boys, and the remaining students record the results of each touched the ball and see what results arise

2, to experience unfair division: the results, who won the ah (Girls) girls really simple ah, congratulations girls achieved victory. Boys have something to say?

(Boys: not fair!)

Division: how unfair

Boys: the white box the ball more than the yellow ball, the girls won the likelihood)

Division: a good answer! In life, the only reasonable and fair thing to make everyone satisfied. That s how the game is fair and reasonable? Today we have to study the fairness of the rules of the game (to produce topic, students Qidu topic)

(Design ideas: Play touch the ball game, so that students feel unfair competition, the students triggered awareness of the problem and how the rules of the game is fair )

Second, the layers of Inquiry, to solve the problem (a) According to experience, to solve the problem

1, Kejian rest, naughty and Xiaoxiao ready to play chess, playing chess or whoever the decision, they are humility: You first, to you first. Can you help them Xianggebanfa, whoever decided to play chess? (According to answer students to produce courseware: Caiquan, throwing coins, the drawing of lots, to the drawing of lots

Zhi Touzi, if more than 3:00, naughty Xianzou; if less than 3:00, Xiaoxiaoxianzou.

Division: students think that this clever dog s rules of the game fair?

(Health: unfair and Health: fair)

Division: that is not fair to the students talk about why unfair (More than 3:00 opportunities, the chance is less than 3:00 less)

(B) hands-verification, problem-solving division: Such reasoning is indeed reasonable, but Zhenzhi comes from practice, we try to Zhitou Zi. To see is greater than the number of 3:00, 3:00 or less than the number of times more.

Division: Please do a good job in the team division of labor: one elected Zhitou Zi, a total of dice 10 times, one when the record-filled memory cards, other students when supervisors. (Note: When exactly equal to 3 points, as this is invalid, dropped to one.) Biyi Bi which group to abide by the rules and both time and the beginning of the experiment.

Log card:

Log card (Summary):

(Experimental students, teachers on the guide, if a complete record of the computer card to get boost input)

Division: each group of experimental results are summarized here, please observe the observation, you find what

(More than three points more than the number of times)

Division: Why would produce such a result? (Health: Because the only two points more than 1,2 two possibilities. 3 points higher than the 4, 5, 6 are three possibilities.)

Division: So we found through the experiments of this clever dogs develop the rules of the game is fair?

Health: unfair.

Division: If you are Xiaoxiao, you are willing to play the game so unfair? Health: do not want to.

Division: It seems that only fair rules of the game was fun, the students have only willing to play. Qingtongxuemen starting their own minds think about how smart the dog to amend the rules of the game, to be both naughty and Xiaoxiao fair? To modify their approach in the group say.

(A name that, a few naughty Xianzou single, double the number Xiaoxiaoxianzou 2, who is throwing the big points, who Xianzou 3, to the point of throwing naughty Xianzou 1, 2, 3, 4, 5, 6 points for Xiaoxiaoxianzou 4, more than 3:00 naughty Xianzou, less than or equal to 3:00 Xiaoxiaoxianzou.)

Division Summary: No matter how changes to make both the possibility of the same to be fair.

(Design ideas: 1, through discussion, so that students more than three points clear of three possible, less than 3:00, only two possibilities, that this approach is not fair. 2, by guess, to enable students Forecast for the trial in which the number a little more, know how large the number of possibilities will be more. 3, through analysis of data summary table and understand the reaction of information, training students awareness of the problem, and further understand the phenomenon of uncertainty.)

Third, the application of science, application development

1, determined players. Strive to become lucky star of the game only eight students to participate in, how do (Eight groups each elect one person.) Elected representative of the group and talk about how the election.

2, entries:

First Off: 8 into four or eight cells to produce multi-media, were hidden inside the customs clearance and information, however, contestants choose from;

The second clearance is pumped games, four into two, who

Poker is 8 will be able to enter the third Commissioner. (For four cards, two 8)

The third is the final clearance, we are prepared to use dial to decide the outcome, who is going to formulate the rules of the game for them.

(Design intent: This activity can greatly arouse the enthusiasm of the students, and allow all students to participate in, let students make comprehensive use of knowledge by the choice of participants and to stimulate the potential of students.)

Fourth, return to reality, to solve the problem

1, the division: only fair game everyone was willing to play, but in life we will not meet the fair, please listen to this dialogue.

Student: Auntie, I bought a fountain pen sales people: to, nine yuan 8 Kok students: not read the prices on nine yuan 7 corner five minutes?

Sales people: children, now do not have the coins, use the rounded!

Student: rounding of the law fair? Customers

Division: Please discuss discussion, rounding off of the law fair? Customers

(Software) into the five are: 5,6,7,8,9 value of five points, four homes were: 1,2,3,4 four points value, businesses can earn income: 5 +4 +3 +2 +1

Division: Although only five of the poor, but if a lot of customers, money is very big, let us look at this information. (Produce courseware: Zhengzhou, a world of medium-sized supermarkets because of rounding the coins, one day may be three more than 100 yuan more income, more than 1,000 yuan a month is 9, 2001 is 100,008 more than 1,000 yuan. Rounded and not Fair, how the only fair way to this issue on the left to the students after school to discuss.)

(Design ideas: to use the school to resolve the problems in life, feelings of the value of mathematics.)

2, Xiao Ming and Xiao-Lan do touch the ball game, every time an arbitrary touch the ball, and then put them back. Bai Xiao Ming touch the ball in 1 minute, and reached the ball Huang Xiaolan in 1 minute, and reached the ball the other colors Xiao Ming and Xiao-Lan not score, you think in a few pockets where it is fair to touch the ball

Bag

Xiaoxiao games, but not the rules of the game, let us think about how to formulate the rules of the game fair and write this on the operations.

5, summing up the whole course:

Through this lesson learning, you harvest what is the largest On your own, the students and teachers in this class? Satisfied with the performance of

Teaching Reflection:

First, import courses designed to have doubts about thinking and explore. I designed the classroom closer to student life, challenging the issue of context, boys and girls playing touch the ball game, the students triggered awareness of the problem: This game is not fair, a must in order to make both sides a fair way of the game! So that students have a learning needs! In this way, students need a dynamic, therefore

Second, I think that this lesson is the successful design of practical applications of the two situations. First, people encounter in their daily shopping in the sub-currencies rounding off of his customers in the end? Fair That is, in our usual shopping in the now rarely-used currency, rounded method seems to have become a natural act, either on this lesson, I did not really thought about this in-depth approach to the Fair and unfair to customers in the end, this life of the practical problems raised to allow students to use this lesson to learn Discrimination, I think students will feel that the value of math, there will be a successful good, there will be Huangrantaiwu feeling, The original rounded method is not fair ah. Final design of a lucky stars become the game, so that all students are learning Fun activities to full participation in the past, but also in activities can make comprehensive use of the study, design fair rules of the game, so that students are learning from experience , Learning to use.

Third, puzzled:

1, data often can not describe the problem how to do Zhi Touzi done in the game, I Henpa a less than 3:00, more often, as that will not be able to more than three points than the possibility of less than 3:00, the possibility of larger. I have prepared in advance, if they are less than 3:00, the more, then each group to increase the number of experiments.

2, how to make students better experience uncertainty phenomenon Star fortunate in becoming the first Commissioner, just in front of four students are very fortunate to be elected through the information, the students said teachers such unfair: the first election through the probability of relatively large, I was only Changed the game: the drawing of lots game. In fact, I do not know ahead of the election will be all clearance , it is a coincidence, that is not identified. I think the first Commissioner of the game is fair, but students say that is unfair, how to make students more in-depth experience in this uncertain