Download presentation angles. Presentation for the lesson "Angle. Types of angles" (Grade 2) Educational complex "School of Russia". IV. Working on new material

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1 2 3 4 Time unit 2. Mass unit 3. One hundredth part of a number 4. Tool for measuring the length of segments M INUT A G R A M M P R O C E N T L IN E J K A IIII I IIII I IIII I IIII I IIII I IIII I IIII I IIII I IIII I IIII I IIII I IIII I IIII I 0 1 2 3 4 5 6 7 8 9 10 11 12 Gram

straight beam segment

How did this figure come about?

An angle is a shape formed by two rays emanating from one point. O A B AOB Side of the corner Top of the corner

The sign to indicate the angle was introduced in the 18th century by the French mathematician Pierre Erigon Erigon used the sign to indicate the right angle

Use the "" sign to write down the angles shown, indicate their sides and vertices. M O K A V S If you completed the task correctly, then you have written down:  WHOM: OK and OM - sides  WHOM O - top  WHOM  YOU: AB and AC - sides  YOU A - top  YOU

Look closely at the drawing. It shows points that belong to  ABC and do not belong to  ABC. So, points P, E, D, K belong to  ABC, points M, O do not belong to  ABC, and points P, K lie on the sides  ABC. A B S R K E D M O

Look carefully at the figure and name the points that belong to  ROD and do not belong to  ROD. If you completed the task correctly, then you have named points: Points T, A, B, C, K belong to  ROD. Points M, H do not belong to  ROD. R O D T S V A N K M

A = B A B A C A

Equal angles when overlapping coincide If one corner is superimposed on another and they coincide, then these angles are equal or

SHARP BLUNT STRAIGHT EXTENDED

О А В Two beams complementary to each other form a swept angle

Look closely at the drawing. Write down the angles in ascending order of magnitude. If you completed the task correctly, then you have it written down:  AVD,  ROS,  MKE K M E R O S V A D

Hour 1 2 3 4 5 6 7 8 9 10 11 Angle O O P T T R T T P O O About 12 3 9 6 1 2 11 10 5 4 7 8 Determine the type of angles that form the hands of the clock. CHECK O - SHARP P - STRAIGHT T - BLUNT P - EXTENDED

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Theme: Injection. Types of angles. (Textbook "Mathematics Grade 2 Part 2

Goals: form an idea of the types of corners; improve computational skills and the ability to solve problems, develop logical thinking. To foster in students the relationship of business cooperation (goodwill to each other, respect the opinions of others, be able to listen to friends), accuracy, instill interest in the subject.

Planned results: students will learn how to determine the types of angles (acute, obtuse, straight) using the angle model; recognize geometric shapes; check the correctness of the addition and subtraction actions; explain and justify the action to solve the problem; monitor and evaluate your work and its results.

Equipment: for children - a drawing square, a sheet for a right angle model, a card with corners, a counting book... For the teacher - Presentation, projector, document camera and sample of solved examples, square, signs "Types of corners", "Parts of an angle", drawing of a figure.

During the classes.

Stages:

Teacher activity

Student activities

Note

I. Organizational moment.

Creating conditions for maintaining interest in learning.

The long-awaited call is given

Lesson begins!

What qualities do we need in a math lesson?

You are still studying, but you can already be called connoisseurs, because you already know and can do a lot. And today you have to answer many questions, as befits connoisseurs, as well as learn something new, because a person lives while learning and learns something new. Guests came to our lesson. They want to see how you can work.

(children speak with the teacher)

Children's answers

(children, together with the teacher, speak and perform actions)

I will open the notebook

And I'll put it down with a tilt.

I, friends, will not hide from you:

I hold the handle correctly!

I won't even bend to sit down,

I'll get to work!

(We write the number. Cool work)

II. A minute of calligraphy.

260 260

how to write 2 correctly? 6? 0? We write a line.

Let's talk about the resulting number

(children in a chain): this number is two hundred and sixty; it is three-digit; it has 2 hundreds, 6 tens of 0 units; its neighbors 259, 261; it can be obtained from neighbors if 259 + 1 or 260-1; this number can be replaced by the sum of the bit terms 200 and 60; only dozens of this number are 26; total units 260.

Education for neatness

II I. Actualization of knowledge. Self-determination to activity

Preparation and attitude of students to the introduction of new material, the development of rational and intuitive abilities

There is no need to stand still

To be bored from idleness

We'll try everything together

Learn something new.

All attentive, inquisitive

Important discoveries await.

On the road of school knowledge

They will lead everyone to success!

Under this motto we will conduct this lesson. Let's start with verbal counting

A)- Fill the table

Minuend

Subtraction

Difference

What is unknown in the first column? How did you find it?

What is unknown in the second column? How did you find it?( To find the subtracted, you need to add the difference to the subtracted. To find the subtracted, you need to subtract the difference from the subtracted.)

B)- Solve tasks

There were 2 birches, 4 apple trees, 5 cherries in the garden. How many fruit trees were there in the garden? (nine)

Sister is 9 years old, brother is 3 years old. How much will your sister be older than her brother in 5 years? (6)

How to call it in one word: What is it? (geometric figures). What 2 groups can they be divided into.(I group - there are corners; II group - no corners.)

Say the name and which group you want to include.( In the first group of figures 1, 3, 5; in the second - figures 2, 4.)

What is the name of the science that studies geometric shapes?(GEOMETRY)

Today we are invited by the Queen of Mathematics on a journey through the field of Geometry. To find out the purpose of the trip, you need to solve the Geometric crossword.

G) 1) A part of a straight line that has a beginning but no end. (Ray).

2) A geometric figure that has no corners. (Circle).

4) A geometric figure in the shape of an elongated circle. (Oval).

Children calculate and show the answer with a counting book

explain and justify the action to solve the problem

Children's answers.

Improving Computing Skills

Development of logical thinking

IV. Statement of the educational problem

Developing the ability to plan activities

What do you think: what is the topic of our lesson? What educational tasks will we set for the lesson?

Children answer what they want to know: What is an angle. Types of angles.

V. Discovery of new knowledge

Development of activity abilities

Primary consolidation of the concept of "angle"

Summing up (intermediate)

A) How many of you have heard the word corner in everyday life? Corners surround us in everyday life. Give your examples of where there are corners around us. (Look at the screen.) Shown here is a metal corner for connecting pipes, a stationery corner, drawing squares, corner furniture: a table, a sofa.

Let's start discovering new knowledge.

B)- Think about what tools we need in the lesson? (ruler, triangle, pencils)

In a notebook, mark a point and mark it with the letter O. Draw two rays from point O. How many parts have the rays divided the plane? Shade the smaller part with a colored pencil.

Which shape did you shade? (Injection).

Formulate a definition.

A figure that consists of a point and two rays emanating from this point is called an angle.

An angle is a geometric figure formed by two different rays with a common origin.

Point O is the apex of the corner. An angle can be called a single letter written near its top. Angle O. But there can be several angles with one vertex. What to do then?

In such cases, if you call different angles with the same letter, then it will not be clear what angle we are talking about. To prevent this from happening, on each side of the corner, you can mark one point, put a letter near it and mark the angle with three letters, while always writing a letter in the middle indicating the top of the corner. Angle AOB.

What are the names of the rays coming out of a point? (Sides.) Formulate the definition and show the sides in the picture. The beams that form an angle are called sides. Beams ОА and ОВ are the sides of the angle.

V) Do you see the same angles on the screen?(No.) It's time to find out the types of corners.

1 2 3 4 5

6 7 8

Practical work... Building a model of a right angle.

The angles are different, but first we will get acquainted with the most important angle. Take a piece of paper. Fold the sheet in half and then in half again. Draw the fold lines with a pencil. How many parts did the straight lines divide the plane into? (Four).

How many angles did you get? (Four).

These are special angles. Maybe someone knows the name of these corners? (These corners are straight.)

Draw a dot at the intersection of the fold lines. Mark one right corner with letters. Shade the inside with a colored pencil.

It is not always convenient to determine the right angle by eye. To do this, use a square ruler. To determine whether or not an angle is right, you need to align the vertex and one side of the angle with the vertex and side of the right angle on the square ruler. Find a right angle on it with your model. If the sides of the model coincide with the sides of the square, then this is a right angle.

Exercise: Using the right angle model, find right angles in the picture and write down their numbers.

The figure shows that there are other angles - not straight. Is it possible to compare angles in magnitude. Each of the corners has its own name.

An acute angle is an angle that is less than a right angle. An obtuse angle is an angle that is greater than a right angle.

Use the right angle model to find out if the other corners of the square are right. We see that the angle of the square is less than the right angle, so what is it?

Let's check the third corner. We will overlay the model of the right angle on the angle of the gon and compare. So what is it called? (sharp) So, the drawing square has 1 right angle and 2 acute angles.

G) Let's define the types of corners using the right angle of the drawing square. If the sides of the corner and the right angle of the square coincide, then what is the angle? (right) If the angle is less than the right angle of the square, then this is ...? (acute angle) If the angle is greater than the right angle of the square, then it is an obtuse angle.

What types of angles are there? (hang up a sign) What are the sharp corners? Name the obtuse corners.

Children's answers

Practical work

(Children perform task in pairs, then one student names his answer, everyone checks the work).

Fostering in children a relationship of business cooperation (goodwill to each other, respect the opinion of others, be able to listen to comrades),

Vi. Fizminutka

Health-saving technology

(children speak and do exercises) All the guys stood up together

And they walked on the spot.

Stretched on tiptoes

And turned to each other

We sat down like springs

And then they sat down quietly.

Vii. Anchoring.

A) According to the textbook p.9 №2 ... What do the examples have in common?

What two groups can all examples be divided into? (I group examples for addition, II group for subtraction.)

B) Solving problems No. 5, 6(orally)

C) Test. I read on the screen

3) 3.

Solve 1 and 2 examples with commenting. 3 - 5 examples yourself. Cross-reference - against reference (projected through the document camera)

the student reads.

Show: What time is the task?

Show the answer.

Explain the solution

Day-Night game: children show the answer with their fingers

Improving writing computation skills,

check the correctness of the addition and subtraction actions

Explain and justify the action to solve the problem

Control and evaluate their work and its result

VIII. Reflection

What new did you learn in the lesson? What are the elements of the corner?What angles are there?

What kinddid you set educational tasks for the lesson?

Our journey through the country ends with Geometry

What can you say at the end of the lesson? Rate your work: if you are satisfied with your work, you have succeeded, then the yellow circle. If you were wrong a little, but realized your mistakes. That is a green circle. If you need help to understand new material then raise the red circle.

In the future, in the lessons of mathematics and geometry, we will learn a lot about different geometric shapes.

Children's answers

self-esteem

Evaluate their work and its result

I X ... D / Z

p.8 (ave.) p.9 No. 1, 3.

Estimates. Thanks for your work.