What are the terms of addition called? Names of multiplication components. Explanation of new concepts

TOPIC: Names of numbers for addition and subtraction. Commutative property of addition. Adding and subtracting numbers by parts. Adding and subtracting two-digit numbers without jumping through place value. Problems on finding the sum and remainder, on difference comparison. Comparison of numbers. Units of length. Comparison of lengths of segments.

Let's remember the material we studied: read and tell.

· The numbers used to count objects are called natural numbers.

· Integersform natural series of numbers: 1, 2, 3, 4, 5, 6, 7, 8, 9. 10, 11, 12, ……. The smallest in this series is number 1, greatest there is no number in it. This series is constructed in such a way that each next number is one more than the previous one.

· Numbers that are written as one digit are called single digit numbers; numbers that are written with two digits are two-digit.

· When writing a two-digit number, the digit on the right represents units, and the digit on the left represents tens.

· Reminder for bitwise comparison of numbers

1. Comparing tens numbers: greater is the number in which there are more tens; less is one in which there are fewer tens.

2. If there are equal numbers of tens, then comparing the numbers of units: a larger number is a number that has more units, a smaller number is a number that has fewer units.

· Addition numbers: first term, second term, sum

· Commutative law of addition:Rearranging the places of the terms does not change the sum.

· Subtraction numbers: minuend, subtrahend, difference

· Components of the task:

1. Condition, question

2. Numeric data, required

3. Brief entry, diagram

4. Action selection

5. Solution

6. Answer

· Inverse problems - these are tasks that describe one plot, contain the same numbers, But In one problem, a certain number is the desired one, and in another problem, this number is given.(what you are looking for becomes given, and given becomes the desired one)

· Think about it this way: To answer the question of the problem, it is enough to know two numeric values. We will answer the problem question arithmetic operation…..(by addition or subtraction)

· Difference comparison problems- the question of the problem sounds like this: How much more (less) .....?

Let's move on to the practical part.

1) Write down the date, Cool job

2) Divide the set of numbers into two subsets. On what basis can this be done? Underline the units with one line, the tens with two.

91243307197458368

3) Replace the numbers with the sum of the digit terms: 13, 24, 65, 11, 28, 87

4) Remember the composition of the numbers 2 - 10.

5) Write down the numbers of the 7th ten.

6) Write numbers containing 5 ones

7) Insert such numbers to obtain true equalities.

69 + …= 7060 + …= 907…- 70 = 3

55 - … = 5480 - 6.. = 20 Homework: No. 37, 41 p. 8

This lesson is devoted to the topic: “Names of multiplication components.” The components of each mathematical operation have a name. In this lesson, we will remember in which cases we can replace addition with multiplication, and learn the names of the components of multiplication. To consolidate new knowledge, we will perform several test exercises.

In this lesson we will learn the names of the components of multiplication.

Let's complete the following task:

Exercise 1

Look at the following expressions:

Can addition be replaced by multiplication in all cases? Where possible, replace addition with multiplication.

Let us remember that addition can be replaced by multiplication where the sums of identical terms are found. This means we can replace addition with multiplication in expressions 1 and 4.

Just like in addition and subtraction, numbers in multiplication have their own name. The first number when multiplying is called factor. The second number when multiplying is also called factor. The result of multiplication is called work.

multiplier · multiplier = product

• Five times two equals ten.
• Double the number of five and you get ten.
• The first factor is five, the second factor is two, the product is ten.
• The product of five and two equals ten.

Consider the following task. Let's find the value of the expression 2·9 if we know that 2·8=16. 2·8 is two repeated eight times (Fig. 1).

Rice. 1. 2 8 - this is two repeated eight times

2·9 is two repeated nine times (Fig. 2), that is, one more time. This means that if we add 2 to the result of the expression 2 8, we get the result of the expression 2 9.

Rice. 2. 2 9 - this is two repeated nine times

Now let's try to find out the meaning of the expression 2·7. 2 8 is two repeated eight times (Fig. 1), and 2 7 is repeated two seven times (Fig. 3), that is, one less time, which means to get the result given expression, it is necessary to subtract 2 from the result of the expression 2·8.

Rice. 3. 2 7 - repeat two seven times

Now we know what numbers are called when multiplied, and we will be able to use these terms when reading expressions.

The components of each mathematical operation have their own name.

When adding:

term + term = sum

When subtracting:

minuend - subtrahend = difference

Bibliography

1. Alexandrova E.I. Mathematics. 2nd grade. - M.: Bustard, 2004.
2. Bashmakov M.I., Nefedova M.G. Mathematics. 2nd grade. - M.: Astrel, 2006.
3. Dorofeev G.V., Mirakova T.I. Mathematics. 2nd grade. - M.: Education, 2012.

1. Festival.1september.ru ().
2. Shkolo.ru ().
3. School-assistant.ru ().

Homework

1. Learn the names of the components of multiplication.
2. Read the following equations:

Lesson 47. ADD AND SUBTRACT NUMBER 2.

NAME OF NUMBERS IN ADDITION

Lesson objectives: strengthen students' ability to add and subtract the number 2; introduce students to the names of numbers when adding; continue preparatory work to study the topic “Task”.

During the classes

I. Organizational moment.

II. Strengthening students' ability to add and subtract the number 2.

The teacher can offer the children game "Make a Train".

(All trailers must be arranged in ascending order of results.)

III. Learning new material.

1. Explanation of new concepts.

The teacher asks students what groups all the trailers can be divided into. (Children can identify many groups, but the teacher should pay special attention to the groups associated with the choice of the action sign, that is, one group is examples for addition, the other is for subtraction.)

Then the teacher tells the students that today in the lesson they will consider in detail only one group, the one where the action “addition” is performed, and then informs the children that the numbers that add up are called terms , and the result of the addition is called amount .

After this, the teacher posts a table on the board:

Names of numbers when adding

2. Reading equalities using new terms.

The teacher trains children in reading examples using the terms “command” and “sum”.

For example: the first term is 4, the second term is 2, the sum is 6. The sum of the numbers 5 and 2 is 7.

Working with students on the use of the terms “first term”, “second term”, “sum of numbers” is carried out according to task 2 (p. 78 of the textbook, part 1).

In the same task, students will meet differences . The teacher asks students a question:

Or before starting work on the assignment, the teacher asks the children to find only the sums.

IV. Formation of numeracy skills.

Students complete task 3 with commentary (p. 78 of the textbook, part 1), while the teacher draws the children’s attention to read expressions differently when commenting. For example: “The first term is one, the second term is one, the value of the sum is two. The sum of the numbers two and one is three. Two multiplied by two equals four. Add one to three and you get four.” Etc.

V. Propaedeutics of the topic “Task”.

One of the students reads problem 4 (p. 79 of the textbook, part 1).

– What is the story you read about?

– What is known in the story? (It is known that Vasya had 6 books and was given 2 more books.)

– What do you need to know? (How many books does Vasya have?)

– What arithmetic operation should be performed to answer the question posed? (Addition.)

– Why do you think so? (Because Vasya has more books.)

Problem 5 is analyzed in a similar way (p. 79 of the textbook, part 1).

VI. Independent work of students.

Students independently (preferably in pairs) complete task 2 (p. 21 in notebook No. 1): they obtain the number 4 in different ways by connecting these numbers with pencils of different colors.

For example:

FRONTAL CHECK.

VII. Strengthening the ability to add and subtract the number 2.

At the end of the lesson, students complete task 6 (p. 79 of the textbook, part 1), explain which of the fairy-tale characters was wrong. (The hare was mistaken, since he had to perform the action “addition”; when adding, the number increases, that is, the hare had to take two steps forward, not back.)

VIII. Lesson summary.

– What new did you learn in the lesson?

– What are the numbers that add up called?

– What is the name of the result obtained from addition?

Abstract open lesson mathematics

Subject: Name of numbers when subtracting

Target: create conditions for familiarization with the names of numbers when subtracting; developing the ability to solve problems and expressions, mental calculation skills.

Planned results (subject): know the names of numbers when subtracting; be able to solve problems and find the meaning of expressions.

Universal learning activities (meta-subject):

Regulatory: be able to carry out control based on the result (retrospective), control the result at the request of the teacher; distinguish a correctly completed task from an incorrect one.

Communicative: be able to listen and engage in dialogue, participate in collective discussion.

Cognitive: be able to perform logical actions: analysis, synthesis, choose grounds for comparison, seriation, classification of objects, establish analogies and cause-and-effect relationships, build a logical chain of reasoning; relate objects to known concepts based on the implementation of universal logical actions.

Personal: act in accordance with the handling instructions teaching aids, visual and counting materials, tools for constructing geometric figures and working rules.

Lesson script

1.Org.moment (Checking the readiness of the class and equipment; emotional mood for the lesson (cards on desks)

Invented by someone simply and wisely
When meeting, greet: “Good morning!”
Good morning to the sun and birds!
Good morning to trusting people!

And everyone becomes kind and trusting.
Good morning lasts until evening.

U: I hope you are in a good mood today, let's check it at the beginning of the lesson. In front of you are cards with pictures of little men. One of them smiles, and the other is sad. Choose one of them. If you are in a bad mood, we will try to lift it during the lesson, and those who are already in a good mood will go on to new knowledge in a good mood

- Let's check your readiness for the lesson.

Well done! Let's open the notebooks, step back...write down the number, great job.

2. Calligraphy minute.

3.Repetition of studied material and preparation for the perception of new material

On the desk:

8-2= 6+3= 1+7= 8-4=

9-4= 5+2= 2+6= 7-3=

T: -What two groups can these expressions be divided into? (some examples are for addition, others are for subtraction)

Guys, how many of you remember what numbers are called when adding? (term, term, sum)

Do we know what numbers are called when subtracting? (No)

Who can help formulate the topic of the lesson? (name of numbers when subtracting)

Guys, before class, while we were in the cafeteria, someone slipped a letter to us. Let's read it. Who is it from? (A note from Koshchei is read by a child)

What, guys, are we going to save the names? (yes)

Then get to work.

4.Oral counting

On the desk individual work.

1 person (Solve examples):

2 people (Insert numbers into the missing cells)

3 and 4 people (Fish Game) One student catches fish with answer 5, another student catches fish with answer 10.

Everyone else solves problems in verse

1. Brought by the mother goose

Six children on a pond for a walk.

All the goslings are like balls.

3 sons, how many daughters? (3)

Vadim found 6 mushrooms,

And then 1 more.

You answer the question.

How many mushrooms did he bring? (7)

4 ripe pears

They were swinging on a branch.

Pavlusha picked 2 pears.

How many of them are left? (2)

Across the field in a straight line

The ram was going to water.

3 sheep behind you

He led importantly to the watering hole.

How many are there together? Count

And make your own example! (4)

Well done boys! You did a good job. We are already close to our titles. Koschey invites us to choose from three chests. They store gold, silver and our names of numbers. Guess what is in which chest, if the second chest contains silver, and the first chest does not contain gold. (1 chest - names of numbers, 2 chest - silver, 3 chest - gold)

5. Mathematical physical exercise

2+1 we stamp our feet so many times.
Let's clap our palms 3+2 so many times.
4-1 we will sit down so many times.
6-1 we'll bend over now.
1+1 we will jump that much.
Oh yes, the score, play and that’s it!

6.Learning new material. Introducing new terms and names of numbers when subtracting.

1. Let's create a numerical expression after reading the problem about Koshchei.

Koshchei had 7 lives, he had already lost 3. How many lives does Koshchei have left?

What action will solve the problem? (subtraction)

Who will name the solution to the problem? (7-3=4)

How to call the number 7 if it is reduced? (minuend)

How to call the number that we are subtracting? (subtrahend)

The number that is obtained by subtraction is the difference.

2. Work from the textbook (p. 29)

№1. Read the entry and write down an example (1 on the board, the rest in your notebook)

Task 2: Reading and writing subtraction examples using new terms.

Compose and write down the expressions:

Minuend 7, subtrahend 3, find the difference.

The minuend is 9, the subtrahend is 1, what is the difference between the numbers?

№3 Solving the problem.

Prove that this is a task.

Let's read the condition of the problem, the question of the problem.

What supporting words should we write in the condition?

What action will solve the problem?

Solution: 6-2=4.

Let's name the numbers when subtracting. What are the numbers 6,2,4 called? (minuend, subtrahend, difference)

7. Physical exercise. (Attention task (the sheet shows 3 geometric figures. Guys, you need to remember them and draw them in your notebook).

8.Working with EPU, training disk. (task No. 2)

Complete the statements:

I learned in class today...

It was interesting to me…

I like it…

Branch of the regional state government educational institution for students with disabilities health "Altai comprehensive school No. 1" Rubtsovsk

ABSTRACT

math lesson in 2nd grade

“The name of these numbers and what you are looking for when subtracting”