State Institution "Pavlovskaya Secondary School", Uspensky District Open lesson in mathematics Grade 3 Theme of the lesson: "Addition and subtraction of three-digit numbers without crossing the category." (using ICT) Primary school teacher 2nd category
Donets Zh.V. Lesson topic: "Addition and subtraction of three-digit numbers without crossing the digit." Purpose: To introduce the written method of adding and subtracting three-digit numbers without going through the bit unit by calculating in a column; Fix the writing and solving examples for adding and subtracting two-digit numbers in a column way, oral and written numbering within 1000, writing and reading within 1000 Develop mathematical abilities, speech, logical thinking, visual memory; Contribute to the health of students.
Lesson progress: 1. Psychological attitude. 1 slide on the board topic of the lesson In order for us to succeed today, we must remember that we know what we can do what we can do Today in the lesson, as you have already noticed, we will be helped by a projector that will show us interesting slides. Slide 2 I can (add, solve problems, solve equations, find P and S, I can add three-digit numbers) Let's remember what we can do on the topic of our lesson (we can add three-digit numbers without going through a dozen) probably not only add, but also subtract Here the projector gave us slide No. 4 A let's remember the topic of the lesson with you and say what else we can do with you (solve problems to find the sum) And of course I need to be what? (curious, witty, thoughtful, healthy organized, collected) The projector listened to you and highlighted the main qualities. Slide number 5 But to these four conditions there is one condition without which no person can do mathematics. This is Health! Right! What kind of person should be? (healthy) Of course healthy. We all want to be healthy, right? And who can we consider a healthy person? D. - Athletes who eat right, who lead a healthy lifestyle, etc. U. Yes guys healthy man this is the one who leads the healthy lifestyle. That is why today in the lesson we will try to create a healthy lifestyle model, and the motto of our lesson is slide No. 6 Before you is a tree of our decisions with you, but the tree is not simple, it is magical, delicious fruits can grow on it, or nothing can grow, it will depend from your work. We will perform tasks and draw a conclusion in favor of our health. There is a tree in front of you and two green apples have grown on it. But how useful these apples are, we will find out during the game. You have signal cards on the table. The game is called "True False" I call the statement, if it's true you raise a green card, if it's wrong, then a red one. You are ready?
Game: True False A rectangle has all right angles, is that correct? (Yes, a rectangle has all right angles). In any rectangle, all sides are equal, right? (no, the length is greater than the width) the square has all right angles, right? Yes In any rectangle, all sides are different, right? No, the length is 7 cm and the width is 5 cm. In the number 348 there are 3 dec. 4 hundred. 8 units It's right? (no 3hundred 4 dec 8 units) 530 is greater than 630 is that correct? keep it clean, right? (yes answers children) cleanliness is not the main thing do you agree? (No children answer) So let's go back to our apple tree. What kind of apple we will consider useful? (Keep clean) Guys, today it was not in vain that we remembered hundreds, tens, units. The projector helps us again Slide No. 7 Teacher: What do these numbers have in common? (they are all three-digit, the second and third numbers have the same units, they include the same numbers, the first and third numbers have the same tens) We compared three numbers, and now we will compare a lot of numbers Slide No. 8 You have done a good job, but in the meantime 2 more red apples grew on the apple tree. What decision do you think we should make? And again the projector helps us Slide #9 Write down a series of numbers and check the answers Slide #10 The answer is wrong in the second number. The proverb "Trust but verify". Because mathematics is the queen of sciences, where accuracy is one of the main conditions. Guys, it was not in vain that we remembered hundreds, tens and ones. Why do you think the projector arranged these numbers, for what? (to subtract or add) Slide #11 Assign the class to turn these numbers into the difference. With an explanation at the blackboard, and the rest work in a notebook. Well done guys, you got the job done.
Fizminutka. Videoslide You had a very good rest, and in the meantime, two yellow apples appeared on the tree. We chose healthy food. The projector helps us again. What do you see? (task) slide number 12 Task: 36 ducks swam on the lake, and geese in? times less. How many birds were swimming in the lake? (We cannot solve this problem, because we do not know how many times fewer geese are) Can we put the number ourselves and what? We can 4,6,9 U. Guys, what problem did we solve? (To find the sum) What did you do in the first step? Reduced several times. What action was helpful? (Division) On the projector Slide No. 13 Area and perimeter What do you think these letters are? What is an area? (this is the surface of an object) How to find it? (width times length) Right! What is a perimeter? This is the sum of all sides. How to find R? (A + B) * 2 Why do we remember the area and perimeter do you think? Yes, this will be homework. We did a great job, are you in a good mood? And apples grew again on the apple tree. Guys answers. Let's all smile together and have a team relay. Card work. Card number 1 100 19 = 81: ... = 9 3 * ... = 18 18 + ... = 36 36: ... = 6
6 * … 48 48 … = 30 30: … = 3 Card No. 2 100 28 = 72: … = 9 9 * … = 18 18 + … = 36 36: … = 9 9 * … = 45 45 … = 30 30: … = 10
Reflection: Six hats of Bonnot. White hat. I'm in my white thinking hat. Today in the lesson we got acquainted with the addition and subtraction of three-digit numbers without crossing the digit. But we still need to learn how to add and subtract three-digit numbers with a transition through the discharge. Black hat I'm in my black thinking hat. We talk about the disadvantages and disadvantages that did not work out in the lesson. Yellow hat I'm in my yellow thinking hat. I really liked the lesson, as it was unusual, fun, good for health and mind. Green hat I'm in my green thinking hat. The lesson was very interesting. And I want to suggest that such lessons be held in other subjects. Because in the process of the game it is easier to remember.
Red hat. I'm in my red thinking hat. I really liked the lesson. He was interesting and unusual. I liked that mathematics was connected with the outside world and in a healthy way life, which is very beneficial for our health. My emotions have no limits. Blue hat I'm in my blue thinking hat. Today at the lesson we reached the set goal. We learned how to subtract and add three-digit numbers without crossing the digit. emotions, feelings, intuition. Rules for the 6 Hat Method: All speeches begin with the phrase: "I'm in my ... thinking hat ... ". Red hat - Putting on a red hat, we answer the question: How do I feel about this? White hat - information, facts, questions. Putting on a white hat, we answer the questions: What information did we receive? What more information do we need? Yellow hat - advantages "pluses". Putting on a yellow hat, we answer the questions: Why is this worth doing? What are the benefits? Why is it possible to do this? Why would it work? Black hat - shortcomings, fears "cons". Putting on a black hat, we answer the questions: What can go wrong and will it go wrong? Is it true? Will it work? What are the disadvantages? What is wrong here? Green hat - creativity, ideas, suggestions. Putting on the green hat, we answer the questions: What are some of the possible solutions and actions? What are the alternatives? The blue hat is the organization of thought. Putting on a blue hat, we answer the questions: What have we achieved? What needs to be done next? Hat changing rules:
It is advisable to start the discussion in a white hat, that is, it is necessary to collect and consider all available facts. The original data is then viewed from a negative perspective - with a black hat, of course. After that, it is the turn of the yellow hat, and positive aspects are found in the discovered facts. Once the problem has been looked at from all angles and material has been collected for analysis, it's time to put on the green hat to generate ideas that can amplify the positive points and neutralize the negative ones. The teacher, mentally sitting in a blue hat, carefully controls the process - whether the group has deviated from the given topic, whether the participants are walking in two hats at the same time, and also periodically allows them to let off steam in the red hat. New ideas are again analyzed in black and yellow hats. And at the end they put on a blue hat and sum up the discussion.
Dmitrieva Tatyana Arkadievna
Job title: primary school teacher
Educational institution: Municipal budgetary educational institution"Secondary school No. 2"
Locality: Tarko-Sale
Material name: methodical development
Subject: Cards to the topic "Addition, subtraction of multi-digit numbers"
Publication date: 12.01.2017
Chapter: elementary education
Topic: Addition and subtraction of multi-digit numbers.
Card number 1 Find the sum of the numbers. 2342 + 3216 4102 + 2034 +1260 4136 + 3452 38 647 + 41 242 + 20 605 6314 + 3574 247 832 + 699 111 + 102 231 Card No. 2 4208 + 791 39 + 657 + 2450 2362 + 630 39296 + 84 752 ++ 45 586 + 1203 450 003 + 284 + 3575 Card #3 Calculate the amount and check. 190 005 + 87 999 8709 + 13 291 78 500 + 99 900 67 000 + 13 505 157 439 + 7078 178 097 + 237 850 Card no. 6kg + 72t 308kg 24km 305m + 39km 195m 9c 38kg + 4c 72kg 12kg 581g + 13kg 419g 7m 36cm + 109m 87cm Card No. 5 12 rub. 47kop. + 23 rub. 54kop. 1t 567kg + 3t 878kg 428 rub. 09kop. + 119 rub. 57kop. 935kg + 548kg
48m 37cm + 52m 24cm 1km 848m + 2km 763m Card #6 Calculate the difference. 68 389 – 40 309 200 000 – 65809 117 805 – 32 999 12 005 - 797 2700 – 1724 100 500 – 72 341 50 000 – 9730 70 596 – 796 12 658 – 495 9 Card number 7 Subtract and make an addition check: 6458 - 4349 30 000 – 7004 52 735 – 48 418 50 5421 – 60 024 60 700 – 8244 70 200 - 8509 Card no. 30 m 80 km - 36 km 027 m 10 t 175 kg - 670 kg 99 rub. 38 kop. - 89 kop. Card number 9 Do the following: 45 851 + 37 168 - 74 018 247 086 - 72 546 + 625 400 30 108 - 9524 + 16 479 101 101 - 30 307 + 14 800 Card number 10 Solve the problem:
On Sunday, 917 people visited the museum, of which 475 were adults, 148 fewer teenagers than adults, the rest were children. How many children visited the museum? Calculate: 52 019 + 3109 80 500 - 1408 2t 060kg + 1t 720kg 138 m 36 cm - 88 m 19 cm Card No. 11 Solve the problem: 986 kg of carrots were collected from one plot, 198 kg less from the second than from the first. And from the third section, 483 kg more than from the second. How many kilograms of carrots were collected from three plots? Calculate: 20374 - 81 509 98 306 + 404 749 15t 382 kg – 7t 308 kg t less than the second. How many tons of flour are in three warehouses? Perform actions: 835 723 - 96 241 11 877 + 3464 12 km 472 m - 8 km 864 m subtraction): 225 108 + 508 335 Solve the problem: One milkmaid milked 175 liters of milk per day, which is 27 liters less than the other milked. How many liters of milk did the other milkmaid milk?
Card number 14 Subtract and check by addition: 30 207 - 14 538 800 100 - 715 472 Perform addition and check in two ways (addition and subtraction) 17 823 + 32 277 Solve the problem: 198 birches grew on the forest plot, which was on 75 more than oaks. How many oaks grew on the site? Card No. 15 Find an unknown number: X - 4041 \u003d 2368 10 801 - X \u003d 3807 X + 2012 \u003d 4112 1025 + X \u003d 2530 The length of the rectangle is 45 dm, the width is less than the length by 22 dm. Calculate the perimeter of the rectangle. Card No. 16 Find an unknown number: X - 12,201 \u003d 16,799 20,305 - X \u003d 15,308 3025 + X \u003d 5345 X + 2341 \u003d 4896 The width of the rectangle is 28 cm, the length is 57 cm more than the width. Calculate the perimeter of the rectangle. Card No. 17 Follow the steps: 360 987 - 278 549 300 001 - 287 009 187 360 + 198 288 56 720 + 38 618 148 m 36 cm - 98 m 09 cm 9 t 609 kg + 8 t 038 kg
Card No. 18 Follow the steps: 7320 - 5653 56 785 + 5 748 100 054 - 9 875 40 200 - 29 317 53 247 - 1358 125 204 + 407 108 4 km 275 m -2 km 835 m 26 rubles. 28 kop. + 14 rub. 76 kop. Card number 19 Complete the steps: 12 371 - (5428 + 1371) 2077 + (1356 - 477) Solve the problem: 155 watermelons were collected from melons, and 50 less melons. How many watermelons and melons were collected together? Card number 20 Solve the equations: 125 + X \u003d 183 + 54 190 - X \u003d 32 + 18 214 + X \u003d 386 - 21 360 - X \u003d 82 - 32 Solve the problem: There are 150 pages in the book. Nina read 35 pages on the first day. And on the second day, 15 pages more. How many pages are left for Nina to read?
Place of the lesson in the education system: 3 quarter Lesson number 102.
Goals and objectives:
- Educational:
- to consolidate the ability to add three-digit numbers;
- consolidate knowledge of the multiplication table;
- improve knowledge in the field of geometry;
- Educational:
- develop the ability to competently, logically, fully give answers to questions;
- be able to prove, argue their opinion;
- develop diversity mental processes: thinking, memory, attention.
- self-control techniques;
- develop fine motor skills of the hands;
- Educational:
- creation of a favorable psychological climate for the possibility of revealing the potential of each child;
- to form the quality of mutual assistance;
- build confidence in their abilities;
- develop personality through teacher-student relationships
- maintain and improve health
Equipment: board, cards, pictures (hare and fox), ruves, pouch for ruves, geometric shapes.
DURING THE CLASSES
1. Organizational moment
2. Autotraining
Teacher:
The sun woke up in the sky
We guys smiled
We close our eyes quietly
We raise our hands to the sky
Let's take a ray of sunshine
And bring to the heart
Do you feel the warmth of the sun? Open your eyes. Let a warm, friendly atmosphere favor today at the lesson. Sit down please. So, math lesson. Prepare your pens for work. Work with a chestnut with needles, rolling in the palms. Are your hands warm?
Students: Yes.
Teacher: We start writing. Write down the number, cool work
3. Mental account:
Differentiated job
Weak students work on cards orally (chain)
20 x 20 + 400 - 700 - 95
Teacher: And for you guys, I will read arithmetic problems. You must solve them in your mind. The numbers you received also need to be kept in mind. Write down the results of the calculations only when I say: "Write down."
1) Two numbers are given 5 and 3. Find the product of these numbers ... and subtract 10 from the resulting product ... Then subtract 2 more ... Write down the result (3)
2) Two numbers are given 12 and 34. Multiply the second digit of the first number by the first digit of the second number ... Subtract 2 from the resulting number ... and multiply by 2. Write down the result (8)
3) Two numbers 47 and 32 are given. Multiply the first digit of the second number by the first digit of the first number ... and subtract the second digit of the first number from the resulting product
Record result (5)
Share with me your successes. What number did you get?
Students: 385.
Teacher: Tell me everything you know about this number?
Students: Odd, three-digit
Teacher: Well done. While the guys will tell me what they did, you decipher the word using the flowchart. What are your successes? (Those who worked on cards). The boys read the chain at will.
Table 1
Teacher: I am glad for you that you correctly deciphered the word, correctly solved arithmetic problems. Formulate the topic of the lesson. Who guessed?
Students: Addition of three-digit numbers.
Teacher: Set goals for today's lesson.
Students: Strengthen the ability to add three-digit numbers.
Teacher: And my goals are to achieve that you learn to add three-digit numbers; fix the algorithm of action. OUR GOALS MATCH
4.
Guys, a bunny jumped up to visit us today, which was driven out by a fox. What story is he from?
Students: Fox and hare.
Teacher: He needs to build a house. Who wants to build a house for him?
Students: i think everyone wants to do it
Teacher: Building materials are needed to build a house.
We will go for building materials ... And where, let's find out? Let's solve the examples, and the answer will be ready.
Two students one by one at the blackboard. The next two children are in the notebook. The latter I perform myself, deliberately making a mistake. Pupils, noticing this, must prove the correctness of the answer. The children must help me.
226 + 383 114 + 295 312 + 339 324 + 222 215 + 455
MARKET
Explain aloud.
Teacher: What helped you in your decision?
Students: Algorithm.
Teacher: How does the algorithm help?
Students: Clearly defines the order of our actions.
Teacher: What is the problem in the market?
Students: We don't have money and we won't buy anything.
Teacher: Let's try to make some money. Today we will exchange our knowledge for ryuvas. (ruves are currency unit in our school)
On the cards, a certain task corresponds to the number of ruves, by completing it you check yourself with reverse side cards and if you earn a ruve correctly and put it in your wallet.
5. Card work.(examples on the cards for adding three-digit numbers)
- Choose the cards themselves according to the degree of difficulty:
- Blue - 3 ruves
- Green - 4 ruva
- Red - 5 ruves
Rywa Card 3:
341 + 123
356 + 231
445 + 222
Card 4 rywa
873 + 322
456 + 345
342 + 342
465 + 381
Card 5 ruves
348 + 289
268 + 456
398 + 487
239 + 139
477 + 177
Ruves are placed in a purse, which they always have at hand.
6. Physical Minute(during the break between tasks)
Teacher: Have you lost your desire to help the bunny?
Students: No.
Teacher: Good mood? Let's break our heads again. And how do you understand - "break your head"?
Students:"Puzzle" means to think a lot
Teacher: So, you did a great job and earned a lot of ruves. Let's count. How many ruves? (Children fold ruves)
– Can anyone offer another way to calculate? How would it be faster?
Students: Apply multiplication table
Teacher: All these ditches are your common work. Each of you contributed to buy building materials. Let's go buy building materials.
Everyone takes a building material (a geometric figure) and together we build a house.
Build a house out of these building materials.
(Construct a house on a magnetic board)
Teacher: Do you like the house?
Students: Like.
Teacher: Well done! Shake hands. You are good partners.
7. Working with geometric material(task)
Teacher: this house needs to be fenced Let's take a section 120 m wide and 123 m long and find the length of the entire fence. Try to find a solution by applying today's lesson topic.
Student: Need 120 + 123 +120 + 123
Teacher: Please find and work in pairs. Explain to a friend and see how he decides.
8. Reflection
Teacher: Is it easy to make money
Student: No. To earn them you need to work hard.
Teacher: In order to buy building materials, to build a house or buy a car, you need to work hard. Outside the window is the headmaster's car. Get up and look. Do you want one?
Students: Yes.
Teacher: You will definitely have one, and maybe even better. I believe in you that you will be hardworking, as in today's lesson, and everything will always be fine with you. Well done boys! Our lesson went well. What can you be proud of? What were you a little dissatisfied with?
Each student expresses their opinion:
I am satisfied...
I can…
I like it…
I'll set a goal for the next lesson...
Teacher: You are now little suns. Do you know why?
Children: Why?
Teacher: You shine and warm me and everyone with your warmth.
- Thank you for the lesson! What a great lesson!
9. Homework
- Compose examples on addition on the topic of the lesson and solve them on your own.
CARD #1
1. Perform the addition of numbers.
1 + 1 = 1 + 2 = 1 + 3 = 1 + 4 =
2 + 1 = 2 + 2 = 2 + 3 = 3 + 1 =
3 + 2 = 4 + 1 =
2 ... 3 = 5 3 ... 2 = 1
5 ... 4 = 1 3 ... 2 = 5
3. Fill in the gaps ... with the action "+" or "-".
5 ... 1 ... 1 = 3 3 ... 2 ... 4 = 1
1 ... 3 ... 2 = 2 5 ... 2 ... 1 = 2
4. Solve problems.
How many paws do two ducklings have?________
And how many paws does a teddy bear have? _______
5. Solve word problems for addition.
a) Petya has 2 flags. Viti also has 2 flags. Count the number of flags Petya and Vitya have together?
b) 4 wagons were attached to the train, and then another wagon. How many wagons were attached to the train.
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c) On New Year Grandmother gave Ksyusha 2 bunnies, dad gave a crocodile, and mom gave Cheburashka. How many gifts did Ksyusha receive for the New Year?
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d) There were 3 houses by the road. During the year, 2 more houses were built next to them. How many houses are now along the road?
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CARD #2
1. Solve subtraction examples.
| 2 - 1 = | 3 - 1 = | 3 - 2 = |
| 4 - 1 = | 4 - 2 = | 4 - 3 = |
| 5 - 1 = | 5 - 2 = | 5 - 3 = |
2. Fill in the gaps... with "+" or "-" signs.
| 5 ... 4 ... 1 = 2 | 3 ... 2 ... 4 = 1 | 3 ... 1 ... 2 = 2 |
| 1 ... 3 ... 1 = 3 | 5 ... 3 ... 1 = 3 | 5 ... 2 ... 1 = 4 |
| 2 ... 3 ... 2 = 3 | 5 ... 1 ... 1 = 5 | 5 ... 3 ... 2 = 4 |
3. Solve word problems for subtraction.
a) There were 4 pencils in the box. Polina and Valya each took one pencil from the box. How many pencils are left in the box?
b) Sergey prepared 5 liters of juice for his birthday. The guests drank 4 liters. How many liters of juice are left after the birthday?
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c) Pavlik brought 4 to the holiday balloons. He gave 3 balls to his friends. How many balls does he have left?
CARD #3
1. Perform the addition of numbers.
| 5 + 1 = | 5 + 2 = | 5 + 3 = | 5 + 4 = |
| 6 + 1 = | 6 + 2 = | 6 + 3 = | 6 + 4 = |
| 7 + 0 = | 7 + 1 = | 7 + 2 = | 7 + 3 = |
| 8 + 0 = | 8 + 1 = | 9 + 2 = | 9 + 1 = |
2. Fill in the gaps ... with the action "+" or "-".
4. Solve word problems.
a) Count the legs of the two tables? And how many legs have two sofas, and two beds?
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b) There are 5 footballs and 3 basketballs in the gym. How many balls are in the gym?
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c) 3 girls and 4 boys are engaged in the sports section. How many guys are in the section?
d) 3 oaks and 5 fir-trees grow near the road. How many trees are growing along the road?
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CARD #4
Solve subtraction examples.
| 4 - 0 = | 4 - 1 = | 4 - 2 = | 4 - 3 = |
| 5 - 1 = | 5 - 2 = | 5 - 3 = | 5 - 4 = |
| 5 - 5 = | 6 - 0 = | 6 - 1 = | 6 - 2 = |
| 6 - 3 = | 6 - 4 = | 6 - 5 = | 6 - 6 = |
| 7 - 3 = | 7 - 4 = | 7 - 5 = | 7 - 6 = |
| 7 - 0 = | 7 - 7 = | 7 - 1 = | 7 - 2 = |
| 8 - 3 = | 8 - 4 = | 8 - 5 = | 8 - 6 = |
| 8 - 0 = | 8 - 7 = | 8 - 1 = | 8 - 2 = |
| 9 - 3 = | 9 - 4 = | 9 - 5 = | 9 - 6 = |
| 9 - 0 = | 9 - 7 = | 9 - 1 = | 9 - 2 = |
2. Fill in the blanks... with "+" or "-" signs:
| 8 ... 7 ... 3 = 4 | 5 ... 4 ... 6 = 7 | 5 ... 2 ... 6 = 9 |
| 8 ... 4 ... 2 = 6 | 5 ... 2 ... 1 = 2 | 5 ... 2 ... 4 = 7 |
| 8 ... 5 ... 2 = 5 | 9 ... 2 ... 2 = 4 | 9 ... 2 ... 6 = 1 |
3. Solve problems.
a) There were 8 geese walking in the garden. 5 of them are gone. How many geese are left in the garden?
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b) On New Year's Eve, Sveta was presented with 9 felt-tip pens, by September 1, 4 of them were over. How many felt-tip pens does Sveta have left?
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d) Kolya had 10 rubles. For 3 rubles he bought a pencil. How much money does Kolya have left?
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Open lesson in mathematics in grade 3.
Teacher - Sergeeva E.N.
Lesson topic: "Written addition of three-digit numbers".
The purpose of the lesson: to form the ability to perform written addition of three-digit numbers.
Tasks:
Equipment: notebooks, mathematics textbook (author M.I.Moro, M.A.Bantova), magnetic board, stars with numbers, stars with numbers, cards with tasks of three levels, cards with a task, help cards with a written addition algorithm, posters with the image of asteroids, planets.
During the classes:
Organizing time. Creation of psychological comfort.
Guys, today we have an unusual lesson. I see your shining faces. It speaks of your good mood, Means. Our lesson will be good.
Let's read the words written on the board:
Let the harsh winds blow in our faces,
All paths are open to us guys,
We'll rise to the stars, we'll sail the seas
We are seekers, we are trackers.
Think about the words of this poem. What will we do in class? (We will overcome difficulties, fulfill difficult tasks to learn new things.)
Indeed, we will learn a lot, make a discovery and make fabulous journey into the space. In outer space, we will need not to miss a single distress signal. We will help everyone who needs it.
Knowledge update.
Let's see if you are ready for this journey.
On board: 9
(Red stars with numbers: 9, 0, 1; yellow color with numbers: 2, 6, 7; green with numbers: 4, 8, 3.)
Name the numbers that can be formed using red stars. (109, 901, 910, 190)
What does the number "0" in these numbers say? ? (About the absence of some category.)
Name the most small number.(109)
Name the bit composition of this number. (1 hundred, 0 tens, 9 units.)
What is the previous number for him? ( 108) Follow-up? (110)
Name the largest number. (910.) What does the number 0 stand for in this number?
Name the previous number for him. (909) Subsequent. (911)
Make up and name the numbers using yellow stars. (267, 276, 627, 672, 726, 762.) (Numbers are displayed on a magnetic board.)
Name the number that contains 26 tens .(267.)
(2s. 6dec. 7 units)
(2 hundreds and 67 units.)
(267 units)
Name the number that contains 72 tens. (726.)
How many hundreds and ones are in this number? (7s. and 26 units.)
How many units are there in this number? (726 units)
How many hundreds, tens and ones are there in this number? (7 s. 2 d. 6 units)
Make up and name the numbers using green stars. (483, 438, 348, 384, 834, 843.)
Arrange the numbers in ascending order.
Name the smallest number. (348.)
Express it as a sum bit terms.(300+ 40+ 8)
Name the most big number. (843.)
Represent it as a sum of bit terms. (800+40+3)
So, what do all the numbers that you made up have in common. (They are three digits.)
Why are they called that? (They consist of three characters (numbers).)
What are the digits of three digit numbers? (From hundreds, tens, units.)
I see that you are ready for the journey, you can hit the road .(A picture depicting an aircraft is posted on the board.)
Your notebooks today are turning into in-flight magazines.
Write down the number. Classwork.
A red light came on on our control panel. This means that we are asked for help. Landing. It became known that asteroids are approaching the nearest planet from us. We need to change the trajectory of their flight, for this we need to find out the number of each asteroid and arrange them in descending order.
A poster of falling asteroids opens on the board.
(300 + 40 + 5) + (200 + 20 + 4)
(400 + 50 + 4) + (300 + 5)
(600 + 30 + 2) + (20 + 4)
(400 + 20 + 3) + (200 + 50 + 6)
Find the value of each expression in a convenient way. What needs to be done for this? (First add hundreds, then tens, then units and add the results.)
What numbers did you add in each expression.
Arrange the asteroids in descending (removal) order.
Well done! You helped save the planet. Our ship continues its journey. But what is it? The distress signal is heard again. Landing.
Statement of the educational task.
There is a group of earth scientists on this planet. They do their calculations here. But space pirates broke into their station and destroyed the calculations. We must help restore these calculations.
The board is written:
+ 5 7 + 6 4
Look for mistakes. (In the first example, the terms are written incorrectly, and in the second, the calculations are performed incorrectly.)
Write and solve these examples in your notebooks correctly. (One student at the blackboard works independently.)
Verification: pronouncing the correct solution.
Now restore this entry:
+ 1 5 5 + 1 5 2
(A less prepared student works at the blackboard.)
If there is a problem: If there is no problem:
What is the reason for the difficulty? - Than the last example
(Not known algorithm differs from the previous ones?
addition of three-digit numbers.) Three-digit numbers are added.)
What is the topic of our lesson? (Written addition of three-digit
What will we learn in the lesson? (We will learn to build an algorithm for adding three-digit numbers or refine this algorithm.)
"Discovery" of new knowledge by children.
How do you propose to build a new algorithm? (By analogy with the algorithm for adding two-digit numbers.)
How will we write three-digit numbers in a column? (Same as before: ones under ones, tens under tens, hundreds under hundreds.) This is the first step.
How are we going to add? (Same for the ranks.)
2nd step - add the units ...
3rd step - add tens ...
Step 4 - add hundreds...
5th step - read the answer.
Repeat again the algorithm for adding three-digit numbers. (At the same time, helper cards (algorithm steps) are displayed on the board.)
Open your textbook on p. 59. Read the conclusion given in the textbook. Compare it with the conclusion we made ourselves. (They are the same.)
So, it means that we have deduced the correct algorithm.
Fizkultminutka.
Don't look around
You are an astronaut today!
We start training
To become strong and dexterous.
Put your hands to the sides
Let's get the right left
And then vice versa.
One - clap, two - clap,
Turn around one more time.
One two three four,
Shoulders higher, arms wider...
Let's put our hands down
And sit down at the desks again!
Primary fastening.
What discovery have we made? How to perform written addition of three-digit numbers?
Using the derived algorithm, we will perform the rest of the calculations
scientists on assignment No. 2 of the textbook. We work with comments.
(One student at the blackboard.)
The last two examples are my own. (Mutual check.)
6. Independent work with self check.
And finally, the last calculations of scientists. You have task cards on your desks. Tasks of three levels: level "A" is easy, level "B" is medium in difficulty and level "C" is difficult. You can choose what level of tasks you will complete. You can solve tasks and two levels.
(Children choose tasks and complete them.)
| Level #3. Restore the missing numbers. 2 * 3 2 8 * 3 2 6 * 5 * 3 * 5 * 2 * + * 5 * + 3 * 6 + * * * + * 6 + * 1 * + 5 * 3 7 1 2 * 0 2 8 0 7 3 2 9 7 3 9 7 4 1 |
Check if you have followed the pattern correctly. (Answers to tasks are given.)
coped
Doubted
Did not cope
Well done! You have done a good job and the valuable information destroyed by the pirates has been restored.
7. Inclusion of new knowledge in the knowledge system.
We have flown most way. We are asked to land on the planet of robots, where the main robot has failed. To make it work, we need to find out if it has enough parts to repair it.
Read the tasks on the cards.
Task number 1.
On the first day, 250 parts were delivered to the planet to repair the robot, and on the second day, 3 times more. How many more parts were delivered on the second day than on the first?
Task number 2.
On the first day, 254 parts were delivered to the planet to repair the robot, and on the second day, 167 parts more. How many parts were delivered to the planet in two days?
Choose the problem for which we will use the new algorithm for adding three-digit numbers. (Task number 2.)
What is the task about?
What is known about the problem?
What question?
What words for a short note should I take?
What do you need to know for this?
Do we know everything about this?
Can we find out?
How to find out how many parts were delivered to the planet?
Write down your own solution. Complete the addition in writing.
(One student works at the blackboard.)
421 (d.) was delivered on the second day.
Answer: a total of 675 parts were delivered to the planet.
We found out how many parts were brought, but we do not know how many the robot needs for repairs. To find out this number, let's solve the equation:
X \u003d 272 + 347 272
X= 619 + 347
Will the delivered parts be enough for the robot? (Yes.)
Final reflection.
We fixed the robot, it's time to go home. Look what a wonderful constellation we met on the way home.
(The poster opens (the inscription is made of asterisks):
MOOD
Let's take one star as a souvenir. If by the end of your trip you good mood, then take a red star, if good - yellow, not very good - green.
What was the task?
Did you manage to solve the task?
How did you get the new algorithm?
Where can new knowledge be applied?
What did you do well in class?
What else needs to be worked on?
Homework: compose and solve one example for a new one
algorithm; With. 59, no. 4, 5
