Presentation for the mathematics lesson "common fractions". Presentation "Ordinary fractions" presentation for a mathematics lesson (grade 5) on the topic Read all these fractions

Small business 22.01.2024

Small business

Using ICT in mathematics lessons

Equipment:

The teacher has a computer and a multimedia projector;
Students have notebooks, textbooks, pencils, colored pencils, and rulers.

During the classes

Organizing the class for a lesson.

(self-test on the slide).

Work in notebook No. 868.

Read the assignment. What needs to be done? (You need to draw a square with a side of 6 cells, divide it into 3 parts and paint two thirds). In how many ways can a square be divided into three equal parts? (A square can be divided into three equal parts in two ways.) Students complete the task independently. Self-test byslide 24.

How did fractional numbers appear?

It was not always possible to express the result of a measurement or the cost of a product in a natural number. This is how fractions appeared. At first people used simple fractions, , Thus, fractional numbers have joined the family of natural numbers.

In the Russian language, the word fraction appeared in the 8th century, it came from the word “split” - to break into parts, to break.

In the first mathematics textbooks of the 17th century, fractions were called “broken” numbers. The dash in fraction writing began to be used about 300 years ago.

In the old days in Rus', coins were used in denominations of less than one kopeck: penny -kopecks and half - kopeks.

An interesting system of fractions was in ancient Rome. It was based on dividing a unit of weight into 12 parts, which was called ass.

And for fractions obtained by splitting twelfths into smaller ones, there were special names. Even now they sometimes say: “He carefully studied this issue,” which means that the issue has been studied to the end. And the strange word comes from the Roman nameassa – “scrupulus”.

Lesson summary.

What is a share? (Share – each of the equal parts of the unit)

What determines the name of the share? (The name of the share depends on how many equal parts the unit is divided into)

What fractions are called ordinary? Give examples of ordinary fractions. (Records like, called ordinary fractions)

What is the name of the number that is written above the fractional line? What is the name of the number that is written under the fractional line? (The number written above the line is called the numerator, below the line is the denominator)

What do the numerator and denominator of a fraction show? (The denominator shows how many shares are divided into, and the numerator shows how many such shares are taken)

Slide captions:

Come on, check my friend, are you ready to start the lesson? Is everything in place, Is everything in order, Pen, book and notebook? Is everyone sitting correctly? Is everyone watching carefully? Everyone only wants to get a five rating.

Fractions Common fractions

Goals and objectives: Introduce the concept of fraction, half, third, quarter, common fraction, numerator and denominator of a fraction Develop the ability to read and write common fractions using the numerator and denominator Cultivate a respectful attitude towards others, attention

Questions for consideration: Fraction Half, third, quarter Common fraction What do the numerator and denominator of a fraction show From the history of fractions

Mom bought a watermelon. I cut it into 6 equal parts:

Grandma, Grandpa, Dad, two children and myself.

What is a share? A share is each of the equal parts of a unit. Since the watermelon was cut into 6 equal parts, it means that it was divided into 6 shares and everyone received “one-sixth” of the watermelon, or, in short, “one-sixth of the watermelon.”

How are beats written? To record any beat, use a horizontal line. It is called a fractional line. They write:

What does the number below the line show? The number under the line shows how many equal parts (shares) the unit is divided into, the whole is divided into 5 equal parts (shares)

Think and answer. How are shares formed? When one object or unit of measurement is divided into equal parts. What does the number under the line show? The number under the line shows how many equal parts the unit is divided into.

Half. The most famous share is, of course, half. Words with the prefix “half” can be heard often: half an hour, half a kilometer... They divided the whole into two parts - “half”. The share is called half.

Third. The name of the share depends on how many equal parts the unit is divided into. Divided into three parts - “third”. A share is called a "third"

Quarter. If the whole is divided into 4 parts, then it turns out, or in other words they say “quarter”.

What are the other lobes called? And if you divide it into five parts, then what is it “five”, and into six – “six”? There are no such funny words in the Russian language. To name the beats, use the words “fifth”, “sixth”

Complete the tasks. Read the beats What other words can you call the beats: a quarter, a third, a half.

We are overcome by drowsiness, Reluctant to move. Well, do the following exercise with me: One - stand up, stretch, Two - bend over, straighten up, Three - clap your hands, three claps, three nods with your head.

Solve the puzzle and find out what we are about to meet. "Fractions"

Ordinary fraction. Records of the form are called ordinary fractions... Numerator of a fraction Fraction line (fraction line) Denominator of a fraction

Ordinary fractions. Anyone can see the fractional line a mile away. Above the line is the numerator, know, Below the line is the denominator. Such a fraction must certainly be called ordinary. State the numerator and denominator of each fraction

When reading fractions, you need to remember: the numerator of the fraction is a feminine cardinal number (one, two, eight, etc.), and the denominator is an ordinal number (seventh, hundredth, two hundred and thirtieth, etc.) For example: - one fifth; - two sixths; - eighty-three one hundred fifty-second

What do the numerator and denominator of a fraction show? The denominator shows how many shares are divided, and the numerator shows how many such shares are taken. Read the fractions. What does the numerator and denominator of each fraction show?

Write it as a common fraction. Two sevenths Four ninths One hundredth Six eighths Three twenty-fifths Half

Think and answer. What part of the figure is shaded?

Work in a notebook. No. 868.

Homework: Make up assignments on the topic of ordinary fractions, paragraph 23, No. 901, 902 The lesson is over. And again a change. And the noise in the corridor again. We must definitely have time to tell each other about everything as soon as possible.

Well, check it out, my friend,

Are you ready to start the lesson?

Is everything in place?

Is everything alright?

Pen, book and notebook?

Is everyone sitting correctly?

Is everyone watching carefully?

Everyone wants to receive

Just a five rating!

Common fractions

Lesson-competition “Tic-tac-toe”

Lesson objectives:

Summarize and systematize students’ knowledge on this topic;
Foster a sense of responsibility, develop cognitive interest in the subject;
Develop attention and logical thinking.

Playing field

Letter from

Remember

Black

of the past

Decide

box

Erudite

task

Biathlon

Waltz

snowflakes

Lots of trouble with numbers

That's the kind of people they are.

Well, if they stand in a row,

Then they will talk to you.

Look carefully

Read all these fractions.

Lots of trouble with numbers

That's the kind of people they are.

Well, if they stand in a row,

Then they will talk to you.

Look carefully

Read all these fractions.

Lots of trouble with numbers

That's the kind of people they are.

Well, if they stand in a row,

Then they will talk to you.

Look carefully

Read all these fractions.

Lots of trouble with numbers

That's the kind of people they are.

Well, if they stand in a row,

Then they will talk to you.

Look carefully

Read all these fractions.

Lots of trouble with numbers

That's the kind of people they are.

Well, if they stand in a row,

Then they will talk to you.

Look carefully

Read all these fractions.

Lots of trouble with numbers

That's the kind of people they are.

Well, if they stand in a row,

Then they will talk to you.

Look carefully

Read all these fractions.

Lots of trouble with numbers

That's the kind of people they are.

Well, if they stand in a row,

Then they will talk to you.

Look carefully

Read all these fractions.

Lots of trouble with numbers

That's the kind of people they are.

Well, if they stand in a row,

Then they will talk to you.

Look carefully

Read all these fractions.

Mathematical dictation

Examination:

Letter from the past

In the old days, the fraction was called half.

The fraction was called a third. Fraction -

hon. Fraction - half. Fraction

Seven.

Think and tell me what the following fractions were called in the old days:

half a third

tithe

Erudite

Task 1 team :

less than half;
represent a whole.

Task 2 team:

From the fractions written on the board, choose those that

more than a half;
represent half of a whole.

Examination

Solve the problem:

The postman Pechkin delivered 6 letters to addresses, this is part of all the letters in his bag. How many letters need to be delivered to Pechkin's addresses?

Matroskin the cat milked 20 liters of milk from his cow. This milk turned into sour cream. How much sour cream did the happy Matroskin get?

Competition "K"

1 team:

A(), B(), C(), D(), M(), K().

Team 2:

Mark the points on the coordinate ray:

A(), B(), C(), D(), M(), K().

Using a coordinate ray, compare:

Homework:

№ 963, № 970

Thank you!

To my students for their work in class!

Everyone present for your attention!

900igr.net

Shares

Fractions.

Reading

and recording

Basics

property

fractions

Hover your cursor over the section with the name of the topic and click the mouse.

Correct

and incorrect

fractions

Comparison of fractions

How is a unit divided into fractions?

We shared an orange!

There are many of us, but he is alone.

This slice is for the hedgehog,

This slice is for siskin,

This slice is for ducklings

This slice is for kittens

This slice is for the beaver,

And for the wolf the peel!

He is angry with us - trouble:

Run away in all directions!

How many equal slices was the orange divided into?

One of five

equal shares

orange

Share – this is each of the equal parts of the unit

A common fraction consists of a numerator, a denominator, and a fraction line.

The denominator of the fraction shows

n and how many equal parts are the whole divided?

The numerator shows how many parts were taken.

REMEMBER!

… are called rational numbers ordinary fractions or shorter

– in fractions

numerator

decimal point

denominator (how much divided)

The denominator is not zero!

How to record the second beat?

How to write the twentieth beat?

How to record the third beat?

How to write the seventh beat?

Click on each question with your mouse and the answers will appear.

How to write the fourth beat?

How to write a tenth?

One second beat is called

half

One third is called

third

One fourth is called

quarter

How are fractions made from fractions?

How many equal parts is the circle divided into? How many parts of green? Lilac?

Click on the beats with your mouse and you will see how they are recorded.

Fraction

Fraction is either a share or the sum of several equal shares

How to read fractions correctly?

Thirty one

seventy-second

thirty two

seventy-fourth

What are the numbers in fractions called?

Click the cursor on the words “numerator” and “denominator” and you will read their meaning.

Denominator

Denominator shows how many equal parts the whole is divided into

Numerator

Numerator shows how many equal shares were taken

Five fifths

Nine-fourths

Click on the fractions and you will read the names.

Eleven twenties

seven tenths

Three sevenths

two fifths

Click on “check” - each figure will get a name.

Examination

Which two groups can separate these fractions ?

Incorrect

fractions

Correct

fractions

A fraction in which numerator

less than the denominator ,

called correct fraction

A fraction in which numerator

greater than the denominator ,

called wrong fraction

Determine which part of the circle painted over?

What can be concluded?

Determine what part of the square

painted over?

What can be concluded?

If the numerator and denominator of a fraction

multiply or divide by the same thing

non-zero number, then the value

the fraction will not change.

For example: - one fifth;

- two sixths;

- eighty three

one hundred and fifty second

The denominator shows how many shares are divided, and the numerator shows how many such shares are taken.

Read the fractions. What does the numerator and denominator of each fraction show?

Solve the problem:

The nimble mouse Jerry managed to take a piece of cheese and returned for more cheese, but it was not to be...

Which part of the cheese did the mouse take, and which part of the cheese did Tom get?

What proportion of cheese is each piece?

Let's check the answers: 1) ; 2) ; 3) ; ; .

Write as a fraction

Two sevenths
Four ninths
One hundredth
Six eighths
Three twenty-fifths
Half

Solve the problem:

1 . How many hours are there in a day?

2 . What part of the day will pass if the alarm clock shows:

a) 1 hour, b) 3 hours, c) 5 hours, d) 11 hours?

1 . 24 hours

a) 1 hour –

Write in numbers

h Islo:

A) one ninth;

B) one-thirtieth;

C) three tenths;

D) five-sevenths;

E) nine-fifths;

There are 18 balls in a box.
One second part is black balls, one third part is yellow, and the rest are white.
How many white balls are in the box?

In ancient times, whole and fractional numbers were treated differently: preferences were on the side of whole numbers.

« If you want to share

unit, mathematics

they'll make fun of you

and they won’t allow you to do it.” , -

wrote the founder

Athens Academy Plato.

But not all ancient Greek mathematicians agreed with Plato. Archimedes and Heron handled fractions freely

Alexandrian.

Even Pythagoras, who reverently

related to natural numbers, creating the theory of the musical scale, connected the basic musical intervals with fractions.

Image of fractions in Ancient Egypt

In Ancient China, a dot was used instead of a line.

Fractions in Ancient Rus'

½ - “half”, “floor”

⅓ - “third”

¼ - “quarter”

⅙ - “half a third”

⅛ - “half”

⅟ 12 – “half and a half third”

In ancient Rus', fractions

called shares or broken numbers .

The modern system of writing fractions with a numerator and denominator was created in India. Only there they wrote the denominator at the top and the numerator at the bottom and did not write a fractional line.