Addition of 3 digit numbers in a column. Column addition. Algorithm for adding and subtracting three-digit numbers
It is convenient to carry out in a special way, which is called “ column addition" or " column addition" The beauty of this method is that it allows you to reduce the addition of multivalued natural numbers to adding single digit numbers.
In this article we will look in great detail at how column addition of two and more natural numbers. After describing the sequence of actions, we will give solutions to examples corresponding to all the most typical situations that arise when adding natural numbers into a column.
Page navigation.
What do you need to know to add two natural numbers in a column?
Firstly, it is advisable to know the addition table well. This will allow you to perform columnar addition much faster, since when performing intermediate calculations you will not have to refer to the addition table each time.
Secondly, sooner or later, when adding two multi-digit natural numbers in a column, we will encounter the addition of two zeros, as well as the addition of a natural number and zero. Let us recall the formulations of the corresponding properties of addition of natural numbers:
- if one of the two terms is equal to zero, then the sum is equal to the other term: a+0=a, 0+a=a, Where a– any natural number;
- the sum of two terms, each equal to zero, is zero: 0+0=0 .
Thirdly, we will have to constantly compare the results of intermediate calculations with the number ten, so we need to understand the material in the article comparison of natural numbers.
Now we can move on to describing the column addition of two multi-digit natural numbers.
Column addition of two natural numbers.
We will describe the process of adding a column of two natural numbers together with the solution concrete example. Let's calculate the sum of numbers using a column 724 980 032 And 30 095 .
Column addition begins with writing the terms.
When adding in a column, the terms are written so that the digits that make up the records of the numbers being added are located one below the other, starting from the right. A plus sign is placed to the left of the written terms, and a horizontal line is drawn below.
In our case, the entry will look like this:
Now the resulting record is mentally divided into columns as shown in the figure: 
All further actions come down to adding single-digit numbers in the same column.
Let's present a simplified model of further actions. The process begins with the rightmost column: the numbers in it are added up, the value of the ones place of the resulting number is written under the horizontal line, and the value of the tens place is remembered (if it is different from zero). After this, there is a movement one column to the left and all actions are repeated with the only difference being that the remembered number is added to the sum. The process continues until there are no more columns.
We will describe this process in detail and step by step.
First, the numbers in the right column are added (that is, the unit digits of the original natural numbers are added). If the result is a number smaller 10 , then it is written below the horizontal line in the same column. If the result is a number equal to 10 or more 10 , then the value of the units digit of the resulting number is written under the line, and the value of the tens digit of the resulting number is remembered (this number is used in the next step). For example, if the addition results in a number 16 , then the number 6 write below the line and remember the number 1 , while they say “we write six, one in our mind.”
Thus, in our example we add the numbers from the right column - numbers 2
And 5
. As a result we have the number 7
. Because 7
less than 10
, then we write this number under the horizontal line, and we don’t need to remember any number. We get: 
After this, the numbers in the next column are added up (that is, the tens place values of the original natural numbers are added up), and actions similar to those just described are carried out, but the memorized number is added to the sum (if we memorized it), after which this number is no longer needed keep in mind. If the result is a number smaller 10 , then it is written in this column below the horizontal line. If the result is a number equal to 10 or more 10 , then the value of the units digit of the resulting number is written under the line, and the value of the tens digit is remembered.
So let's add up the numbers 3
And 9
, we get the number 12
. There is no need to add anything to this result, since we did not remember the number in the previous step. Because 12>10
2
12
) and remember the number 1
12
). In order not to forget about the remembered number, we will write it at the top in the column adjacent to the left, and we will use a different color. The entry will look like: 
Let's return to the solution of the example. Adding up the numbers 0
And 0
. As a result we have 0
. To this number we add the memorized number 1
, we get 0+1=1
. Because 1<10
, then write the number under the horizontal line 1
and we don’t remember any number. At this stage, the entry will look like this: 
Let's move on to the next column. We have 0+0=0
. Because 0<10
, then we write zero under the line and do not remember anything: 
At the next step we get 8+3=11
. Because 11
more than 10
, then write down the number 1
(this is the value of the units digit of the number 11
) and remember the number 1
(this is the value of the tens place of the number 11
). We have the following entry: 
The next column contains only one number - the number 9
. Since we have a number in our memory 1
, then it must be added to the number 9
(if we didn’t have any number in memory, we would simply write down the number 9
below the horizontal line). We get 9+1=10
. Therefore, we write the number under the line 0
and remember the number 1
:
We move on to the next column and arrive at a situation similar to the situation from the previous step. Thus we have 4+1=5
. Because 5<10
, then we write 5
below the line and don’t remember anything: 
The next column contains only one number 2
, while there are no numbers in memory. In this case, we simply write this number under the horizontal bar: 
At the last step, the column contains only one number 7, and there are no numbers in memory, so we write down the number 7
under the line: 
There are no numbers in the next column and there are no numbers in memory either. At this point the process can be considered complete.
The natural number formed under the line after the process is completed is the result of adding the original numbers.
So, adding up the numbers in a column 724 980 032 And 30 095 , we got the number 725 010 127 .
Let's look at a few more examples of adding natural numbers in a column to understand all the nuances.
Example.
Add natural numbers 21 And 36 column.
Solution.
Let's write these numbers as required by the column addition method:
Let's start adding the numbers in the right column. We know that 1+6=7
. This number is less 10
, so we just write it below the line. At this stage we have:
Let's move on to adding the numbers in the next column. Because 2+3=5
And 5
less than 10
, then write down the number 5
below the line in the appropriate place:
So, there are no numbers in the next column, and there are no numbers in memory either. Therefore, column addition is completed. We got the following result: 21+36=57 .
Answer:
21+36=57 .
Example.
What is the sum of the numbers? 47 And 38 ?
Solution.
Let's do the column addition:
When adding 7
And 8
we get 15
. Because 15>10
, then write the number under the line 5
, and the number 1
remember:
Now we add the tens place values: 4+3=7
. We add the remembered unit to the resulting value: 7+1=8
. Write down the number 8
below the line in the corresponding column:
There are no numbers in the next column, and there are no numbers in memory either, therefore, the column addition is completed. We have 47+38=85 .
Answer:
47+38=85 .
Example.
Do column addition
Solution.
3+9=12
. Because 12>10
, That 2
we write and 1
in my mind:
Let's move on to adding numbers 8
And 5
. We get 8+5=13
and you need to add another remembered unit: 13+1=14
. Because 14
more 10
, That 4
write down and remember 1
:
Let's move on to the next column: 7+2=9
, and add another remembered unit: 9+1=10
. Received 10
, That's why 0
we write and 1
in my mind: 
Now attention! In the next column, the original numbers being added do not have digits, however, in our mind we have a unit that needs to be written under the line: 
This completes the addition of the original natural numbers, the result is the number 1 042 .
Answer:
783+259=1 042 .
Example.
Find the sum of numbers 56 927 And 90 .
Solution.
Let's do columnar addition. 
Addition 7
And 0
gives 7
. Because 7
less 10
, then we write this number in its place and do not remember anything: 
Obviously, in the next column we only need to add to the number 9
memorized unit: 9+1=10
. We write zero, one in mind: 
In this step we need to 6
add the memorized number one: 6+1=7
. Write down the number 7
in its place, and you don’t need to remember anything: 
Let's move on to the next column. In it with a number 5
There is no need to add anything, that is, we have: 
There are no numbers in the next column, there are no numbers in memory, therefore, column addition is completed.
Answer:
56 927+90=57 017 .
Now let's give an example of adding two natural numbers in a column without intermediate results. This example can be considered as a sample of writing the addition of two natural numbers in a column.
Look, here is a map of our journey.
Each of you have the same cards on your desk. Look at which islands we will visit. During the journey, you will be able to evaluate your work on each island and conclude whether everything worked out for you.
Are you ready? Then let's go.
Show in what mood you are going on your journey.
(EMILITS)
Green - good
Yellow - not very good
Red - bad
1 .First island on the way"QUIET".
Open your notebooks and write down the number.
Cool job.
1 task
Write down the numbers that are 2 tens more than the data... 225, 600, 308,471,708,780.
Let's check, exchange notebooks with your neighbor.
For a correct answer we mark (+), for an incorrect answer (-).
Raise your hands if you don't have a single mistake...
2 task
Write the numbers in increasing order: 210,853,358,609,725,201,906,440.
Let's check. (201 210 358 440 609 725 853 906)
Stand up, those who do not have a single mistake.
3 task
Solve the chain of examples.
Whoever solves it correctly will be the first to know the topic of our lesson.
Do the math..
507+3….+90….+200…+70…+8…+22=880
Let's check the chain.
808- subtraction
900-addition
888-comparison
So, the topic of our lesson is addition….
Let's remember what we studied in the last lesson?
Who can correctly name the topic of the lesson?
What is the goal for the lesson?
To achieve our goal, let's make an action plan…
You have a rough plan on your desks, take pencils and write down the numbers in what order we will work...
1) (3 )Independent solution of examples;
2) (2 )Practice collectively in solving examples;
3) (1 )Remember the algorithm (order) for solving examples
4)(4 )Checking the acquired knowledge
(The plan is posted on the board)
2. There's a new island on the horizon"EXAMPLE".
Who guessed what we will do on this island?...
Let's remember our plan...
(1) Remember the algorithm (order) for solving examples.
Algorithm for adding three-digit numbers.
Adding up the units...
I write the result under units.
I'm adding up tens...
I write the result under tens.
I add up hundreds...
I write the result under hundreds.
I'm reading the answer...
What are we going to do now?
(2) Collectively practice solving examples;
(on the board)
1. Solve the examples, writing them in a column.
(with explanation at the board)
(along the chain)
347+214= 805+79=
434+256= 48+361=
57+128= 714+95=
2.Find and correct errors.
Determine who is right, Masha or Misha?
Masha: Misha:
346 +346
99 99
445 1336
Let's get back to our plan...
3) Independent solution of examples;
You have task cards on your desks. Tasks of three levels: level “A” - easy, level “B” - medium in difficulty and level “C” - difficult. You can choose which level of tasks you will perform.
Level B. Recover the missing numbers. 2 * 3 2 8 * 3 2 6 * 5 * 3 * 5 + * 5 * + 3 * 6 + * * * + * 6 + * 1 *
|
Check if you did it correctly.
(Answers to assignments are given.)
3 . "FUN" island.
Guys, we are mooring to the shore. Let's go ashore, relax, bask in the sun...
Our player, please organize a vacation for us..
What do you think is the task ahead of us?
perform on this island? Right…
Open the textbook on Page 63, read problem No. 5..
Raise your hands, who can solve it?
We decide on our own..
The rest decide with the helper card.
183 rub.
RUR 209
Let's check.
1)209 +183=392(r)
Answer: Mom took 392 rubles.
2.Work in pairs
Page 66, task No. 17.
Listen to the problem.. Discuss which solution you choose and why?
(Check, write down the correct solution in your notebook)
Let's continue our journey. The next island awaits us
5. "TEST"
1.Work in pairs.
1. Come up with 3 examples on our topic for your neighbor….
(Mutual check)
2. Screening test.
Get test cards. Write down your name.
1. Find a number that is less than 700 by 1. a) 600 b) 699 c) 690 2. How much should you add to the number 800 to get 870?
a) 7 b) 70 c) 700 3. If 700 is increased by 250, you get: a) 750 b) 725 c) 950
4. Add the numbers 395 and 143.
a) 583 b) 538 c) 539
5. Find the sum of the numbers 726 and 159.
a) 858 b) 884 c) 885
Check
Our ship returned to port. What goal did we set for the lesson? Do you think we have achieved it?
Continue the statement:
Today in class I learned...
- I liked it...
I found it difficult...
I can use this knowledge...
“Smiley smiley” -
The lesson went well.
I'm pleased with myself!
“Strict smiley” -
It was difficult for me, but I
Coped with the tasks.
I'm quite pleased with myself!
“Sad smiley” -
It was very difficult for me.
I need help!
And I would especially like to highlight the work in the lesson..... You need to be more active...
Please hand over your cards.
Guys, we did a great job. Thanks for the work!
No, because it’s not available for days off...
Math lesson notes in 3rd grade
On the topic:
“Adding and subtracting three-digit numbers in a column”
Work program: SCHOOL 2100
Class teacher: Ivanova Nadezhda Aleksandrovna
LESSON OBJECTIVES.
Educational :
become familiar with the algorithm for written techniques for adding and subtracting three-digit numbers, similar to the same techniques for adding and subtracting two-digit numbers.
consolidate the skill of using the written addition and subtraction algorithm;
consolidate the ability to solve compound problems;
Developmental:
develop mental counting skills;
developing the ability to argue your opinion;
develop children's interest in mathematics and their mathematical abilities;
development of mental activity, cognitive activity, thinking, observation, attention, memory;
developing the ability to self-assess one’s performance;
Educational :
cultivate discipline, responsibility, the ability to empathize, and self-respect; activity, perseverance, diligence, curiosity, interest and inquisitiveness in the learning process;
creating a favorable psychological climate for the opportunity to unlock the potential of each child.
Equipment: personal computer with PowerPoint, media projector, multimedia presentation, mathematics textbooks, flashcards.
Lesson plan:
Organizational point:
1. Greeting
2. Oral counting: 1st task - find the extra number;
Task 2 - decipher the recording;
Task 3 - represent numbers as a sum of digit terms
3.Result of oral counting
Lesson topic message: p. 58 No. 1
Working on a new topic: page 58 No. 2, No. 3
Physical education minute.
Page 58 No. 4, No. 5 (task a, task b)
Lesson summary.
Homework.
Progress of the lesson.
Organizational moment. (slide)
1. Greeting:
The lesson begins
It should be of use to you.
Try to understand everything
Learn to reveal secrets,
Give us complete answers
And don't yawn in class.
Let's start the math lesson. There are guests at our lesson. Greet them. Set yourself up for great work.
Today we will make discoveries, solve examples, problems, develop attention, memory, and logical thinking. Let's set ourselves the lesson:
We came here to study
Don't be lazy, but work hard,
Only the one who knows a lot
You achieve something in life. (slide)
- Open your workbooks, write down today's date, great job.
- 2.Oral counting
Today you continue your journey through the land of three-digit numbers.
What can you do with three-digit numbers? (Read, write, depict using a graphical model, represent as a sum of bit terms, compare, perform oral addition and subtraction techniques)
- Do you think you have all the knowledge about three-digit numbers? (no)
- And before learning something new, you need to repeat the necessary knowledge.
Guys, today I found a letter on the table. It is addressed to our class. Let's read it(slide)
- “Hello, guys. Please help me make a new discovery and
complete all the tasks that Vitya and Kostya have prepared for me. Otherwise, they won’t take me to the circus with them, and I dreamed about it so much. Lika."
And who are Lika, Vitya and Kostya? (Our friends, with whom we are making our fifth trip around the country of Mathematics.)
1 task:
Let's start helping Lika. The letter also contained tasks. Look at the slide (Series of numbers are given)(slide )
76, 53, 458 , 27, 99, 31, 52, 48. (three digits)
548, 460, 752, 300, 76 , 600, 953.(two digits)
300, 100, 542 , 700, 900, 200, 800.(not round)
854, 246, 927, 400 , 299, 762, 127.(round)
325, 121, 102 , 534, 873, 689. (tens missing)
What kind of task do you think can be completed with these series of numbers? Come up with it. (Find the extra number in each group of numbers )
Let's find these numbers and explain why they are redundant.
Well done, but there is a task for these numbers too.
Task 2:
458, 76, 542, 400, 102. (slide)
O V N S O
Look at the remaining row of numbers, it is not ordinary. The recording is encrypted here.
Arrange the numbers in descending order, write them down in your notebook, guess the encrypted word .
Read what word you got. (Nosov) Well done!
What were we able to decipher? (Nikolai Nosov is the author of the story “Vitya Maleev at school and at home”, the heroes of which are Vitya, Kostya and Lika.)
Task 3:
Come up with tasks for this series.(slide)
( Arrange the numbers in ascending order)
Now write down all three-digit numbers in this series as a sum of digit terms.(1 student does it on the board, and the rest in a notebook) (slide)
How many digits are there in each number?(three: hundreds, tens, ones )
How many terms are in each sum?( 3,2,1)
Why is there not the same number of terms everywhere??(no digits)
3. Result of oral counting
So, you and I repeated the numbering and place value terms of three-digit numbers, and also helped Lika cope with the tasks that Kostya and Vitya had prepared, and now she and the guys can go to the circus.
All the guys are great, everyone tried their best, especially…………
But a new topic awaits you and me
Formulating the topic and objectives of the lesson.
1.Message of the topic of the lesson.
– In previous lessons, you solved many examples of addition and subtraction. Let's solve some expressions(No. 1, p. 58). You can see them on the slide.(we’ll say 2 examples out loud, solve the rest yourself ) (slide)
426+231(4s.+2s., 2d.+3d., 6 units + 1 unit)
Which examples were more difficult for you to solve? (The last 2 were hard to solve)
– If it is difficult to verbally add and subtract numbers of this type, then the meaning of these expressions must be found in writing, in a column)
What numbers can we add and subtract in a column? (Double digits)
Explain how our friends Vitya and Kostya added and subtracted numbers?
Slide – 31 31(slide)
19 +19
12 50
What algorithm do we use when recording and calculating? (I write units under units...)
In today's lesson we will learn how to add and subtract three-digit numbers in a column
The topic appears on the slide:Adding and subtracting three-digit numbers in a column . ( slide)
Please tell me how to correctly add/subtract two-digit numbers (I write ones under ones, tens under tens).
And in order to add three-digit numbers, one more digit will be added, namely which one? (hundred) - How will we sign hundreds? (under hundreds)
2. Working on a new topic
Now formulate a general algorithm for adding and subtracting three-digit numbers.
(Children name each step, the teacher records it on the slide)(slide)
Algorithm for adding and subtracting three-digit numbers.
1.I write only a few...
2. I add (subtract) units...
I write the result under units.
3. I add (subtract) tens...
I write the result under tens.
4. I add (subtract) hundreds...
I write the result under hundreds.
5. Reading the answer...
Compare the resulting algorithm with the conclusions in the textbook. Let's read on p.58, in No. 2, No. 3
So, you now know the algorithm for subtracting and adding three-digit numbers, let’s consolidate the knowledge gained.
. Physical education minute. (slide)
But first, let’s give our eyes a rest, everyone raised their eyes to the board and perform those movements with their eyes that will show snowflakes. (Presentation with music, physical education for the eyes)
Primary consolidation. Repetition and consolidation of previously learned.
– Let's begin to consolidate the new topic, complete No. 4 p. 58.
1 example on the board 1 student, we carry out the chain.
Well done. I can also praise the guys who made a mistake. After all, you yourself found your mistake and know what you still need to work on.
Let's do the followingNo. 5 (a) (solution on the board and in notebooks after preliminary analysis.)
Task analysis:
What is this task about?
How many books were there in the library?
How many books were given to 30 students?
What is the question for the problem?
How do you know how many books are left?
What expression will be obtained to solve this problem?
Write down your solution. (1 student on the board, the rest in a notebook)
Solve the problem by letterb on one's own. Solve this problem at the board………..
Lesson summary:
- What did we do in today's lesson?
What new did you learn?
Color your work in class.(slide) Green color shows that your work was successful and the road to further knowledge is open for you. If you still have minor difficulties and need to work a little on the new algorithm, show the yellow card. Red will show that the path to new knowledge is still closed.
Did we help Lika? (Yes)
I want to give a grade to the whole class for their work in class - Well done! I especially liked how they worked in the lesson:…………………
Homework.
P. 59, No. 4 (last column), No. 6 - task;
№ 7 – optional.(slide)
The lesson ends(slide)
Did he benefit the guys?
Have you tried to understand everything?
Have you learned to reveal secrets?
Did you give complete answers?
Did you yawn in class?
Thanks for the lesson.(slide)
Numbers. For example, numbers 3 And 5 :
3 + 5 = 8
It's a little more difficult to add small two-digit and single-digit numbers. For example, 3 And 15 . First number 3 – unambiguous, it consists of units. Second number 15 – two-digit, it consists of units and tens.
In order to add two-digit numbers, you need to add the ones digits of one number with the ones digits of another number, then the tens digits of the first number with the tens digits of the other number.
For column addition Let's place one number under another, ones under ones, and tens under tens. We write the larger number at the top:
Now add the units of the first and second numbers:
5 + 3 = 8
Let's write the answer under units. Now we need to add the tens, but the number 3 no tens and under 1 empty cell. In this case we omit 1 in response to the place of tens. As a result, we get the answer:
15 + 3 = 18
Let's try to solve a couple more examples:
Addition with passing tens
Everything seems simple, but a problem can arise when adding numbers of the same digit results in a number greater than nine.
Let's solve this example:
So, in our example we need to add the numbers 6 And 18 . Add up the units:
8 + 6 = 14
Recording 4 under units, and remember the ten so we don’t forget to write it down 1 over tens.
18 + 6 = 24
Let's try another example:
Now let's complicate the example. Let's add a two-digit number with a two-digit number, passing through ten:
68 + 56
So, let's add up the units: 8 + 6 = 14 ,
4 we write under the units, 1 We remember, so as not to forget, we write above the tens.
Now we add the tens: 6 + 5 = 11 , and add the unit that we remembered: 11 + 1 = 12 .
We write two under tens, and one goes into the hundreds category. As a result we got:
68 + 46 = 124
Thus, you can add arbitrarily large numbers, for example:
In this example, three-digit numbers are added with three-digit numbers, passing through ten.
Add up the units: 8 + 2 = 10 , we write zero in the ones category, we remember the one from ten - we write above the tens.
Adding up tens: 3 + 6 + 1 = 10 , we write zero in the tens place, we remember the one from ten - we write above the hundreds.
Adding up hundreds: 9 + 4 + 1 = 14 , we write four in the hundreds place, and one is transferred to the thousands place.
So, let's summarize.
To add two numbers in a column:
- We write numbers under each other: units under units, tens under tens, hundreds under hundreds, and so on. We write the larger number at the top.
- We add up the units, write the result under the units, if the result is more than ten, then write the units of the result in the units category, and remember the one and write it above the tens.
- We add up the tens; if a one was saved, we add it too. We write the result under the tens, if the result is more than ten, then we write the units of the result in the tens place, and we remember the unit and write it above the hundreds.
- Let's add it up like this, bit by bit. If, as a result of adding the last digits, a unit remains “in the mind,” then we write it in the next digit.
That's it. Thank you for being with us!
Date: Topic: Addition and subtraction of three-digit numbers in a column with transition through place value. Goal: 1. developing the ability to add and subtract three-digit numbers with the transition through digit; development of written oral subtraction skills; 2. development of thought processes; increasing interest in studying mathematics; 3. cultivate the ability to cooperate, as well as the ability to work independently. Equipment: multimedia equipment, grade 3 textbook, part II. PROGRESS OF THE LESSON I. Self-determination for activity. Goal: Involving students in activities at a personally significant level “I want because I can.” Hello guys! Today I will give you a math lesson, my name is Gizatullina Gulnaz Radikovna. I wish you a good mood and good luck in the lesson. Turn to each other, smile and say, “I wish you good luck.” Think about what will be useful for successful work in the classroom? (Belief in success, attention, hard work, diligence, diligence, knowledge.) I suggest you read the motto of our lesson. “We came here to learn, not to be lazy, but to work. Only those who know a lot achieve something in life.” Our lesson today is unusual. What do you think could be unusual in the lesson? Guests came to us. Let's work today so that guests say about us “cool guys!” Do you agree? Then go ahead! Updating and recording the individual II. difficulties in a trial learning activity.
Goal: Repetition of the studied material necessary to “discover new knowledge” and identify difficulties in the individual activities of each student. You have drawings of a tree on your desks. If you answer correctly, if everything works out for you, then you will glue a red “apple”, and if something doesn’t work out, then glue a yellow “apple”. ORAL COUNTING 1. The difference between two numbers eighty and thirty. 2. 3. Product of 5 and 8. There are 4 peaches in the vase, and 6 times more apricots. How many apricots are in the vase? Arrange the numbers in ascending order and read the resulting word. 4. 172 324 603 612 800 K L S H O A Calculate the sum of the digits of each number. What interesting things did you notice? Which number is the odd one out? Why? What numbers do we call three-digit? (We call numbers three-digit when 3 digits are used in their recording.) – Put questions to this data: Girls – 534. Boys – 219. Find the answers. 534 + 219 = 534 – 219 = Children’s answers: (How many girls and boys are there in total? How many more girls than boys? How many fewer boys than girls?) III. Identifying the location and cause of the problem. Purpose: Discussion of difficulties. Why were there difficulties? (We don’t know how to add and subtract three-digit numbers by moving through place value.) Do we know how to do these calculations?
IV. Goal setting and construction of a project for getting out of a difficulty. Purpose: Discussion of a project to overcome difficulties. What will we call the topic of today's lesson? (Adding and subtracting three-digit numbers in a column) V. Implementation of the constructed project. Today in the lesson we will learn how to add and subtract three-digit numbers using place value. Attention to the board: 534 534 219 219 What's wrong? (The addition and subtraction of three-digit numbers in a column is written incorrectly.) What rule should we use when writing and solving these examples? (we write units under units, tens under tens, hundreds under hundreds) Opened the notebooks. We write down the number (January 19. Cool work) We wrote down: 534 219 Who can explain the solution to this example using an algorithm? Algorithm: Adding units... Adding tens... Adding hundreds... Reading the result... Using the algorithm, let's subtract: 534 219 Algorithm: Subtracting units... Subtracting tens... Subtracting hundreds... Reading the result...
PHYSICAL ACTIVITY MINUTE VI. Primary consolidation with commenting in external speech. Goal: Pronouncing new knowledge, recording it in the form of a reference signal (frontal work, work in pairs). No. 5, p. 58 (work at the board) No. 6, p. 58 (select the values of the variables and solve the problem) Kostya needs 3 hours to repair two books. How long does it take to repair 4 books? 6 books? from books? VII. Independent work with self-test according to the standard. Goal: Everyone must come to a conclusion for themselves about what they already know how to do. I century II century 1) 482 + 507 1) 129 + 316 2) 423 – 106 2) 235 + 764 3) 253 + 317 3) 256 – 237 VIII. Reflection on learning activities (lesson summary). Goal: Students’ awareness of learning activities, self-assessment of the results of their own and the entire class’s activities. What task was set at the beginning of the lesson? Did you manage to solve the problem? In what way? What results did you get? What else needs to be done? Where can you apply new knowledge? What did you do well in the lesson? What else needs to be worked on? Homework: No. 8, p. 59
