Scenario lesson

Algebra Grade 8.

Tutorial: Yu.N. Makarychev, N.G. Mindyuk, K. I. Nebkov, S. B. Suvorov.

Teacher: G.P. Whip

Type of lesson: Ons

Theme lesson: "Standard number"

Basic goals:

1) to form knowledge about the standard form;

2) to form the ability to build algorithms on the example of the recording algorithm in standard form;

3) to form the ability to apply the algorithm when presenting numbers in a standard form and actions with them;

Equipment.

Demonstration material:

If aa ≠ 0. and n. - a whole negative number, then

Equipment: Technical equipment lesson - computer, projector for demonstration presentation, screen. Computer presentation in MicrosoftPowerPoint.

DURING THE CLASSES

I.1. Motivation for training activities

Hello guys!What topic did you work on past lessons? Today, in the lesson, you will continue to work with the topic "Degree with an integer and learn something new. Ready to open new knowledge?

What are you always starting to work in the lesson? (From oral work.)

What tasks do you perform at oral work? (Tasks for repetition.)

And for what purpose is the repetition at the beginning of the lesson? (...)

Well done! So what is the next step in work? (Oral work.)

2. Actualization of knowledge and fixation of difficulties in a trial learning action

Make tasks (check on the screen). If you correctly completed tasks, then you should get a word - standard.
What is the standard? Where did you meet with this word? What does it mean?
Standard (from English -standard ) Sample, standard, model with which are compared, such objects, processes compare. (Universal Encyclopedic Dictionary). Those, when they talk about the standard, people are easier to imagine what we are talking about

In the world around us, we are faced with very large and very small numbers.

– Is it convenient to record numbers in this form? Why?(Occupy a lot of space, spends a lot of time, it's hard to memorize.)
- What do you think, what is the yield found from this situation?(Record numbers with degrees.)

We already know with you how to record large and small numbers with the help of the degree of number.

Write down the mass of the earth using the degree of number in different ways. 598 10. 25 G. Now write down the mass of the hydrogen atom. 17 10. –20 is it possible to write these numbers otherwise using degrees? Try! 59.8 10. 26 , 5,98 10 27 ; 0, 598 10 28 ; 5980 10 24 .
17 10 –20 ; 1,7 10 –19 ; 0,17 10 –18 ; 170 10 –21 ;

– All results are correct.

Write down the mass of the earth and the mass of the hydrogen atom in standard form. What is this task for you?

– Who has no answer? What could not?

– Who has an answer? Justify your answer.

3. Detection of the place and the cause of difficulties

– What task was before you?

− Some could not, others could not prove. So we had difficulty.

− Let's deal with what it is.

4. Building a way out of difficulty

What purpose do you put in front of yourself? (Find out the method of recording numbers in standard form and learn how to use this way)

– Word the subject of the lesson.

What means can you use to find out something new? (You can use a textbook, directory.)

– Discover, please textbooks on page 211

Possible Plan Option:

2) Find the definition of a standard type of number.

3) think what signs have multipliers

in definition.

4) make a conclusion that a number may beα .

5) to analyze what is a andn. .

6) make a number record algorithm

in standard video

5. Implementation of the built project

Arrange the correct steps of the algorithm that is on each table.

Put in this numberα command so that one digit is different from zero in the whole part.

Determine the order of the numbern. .

If N\u003e 0, then ≥ 10, if N< 0, то 0< < 1 , если n \u003d 0, then 1≤ <10 (If the order is positive, then the number is greater than 10, if the negative is less than 1, and if zero is zero, then the number is in the interval from 1 to 10)

– In the standard form you can record any positive number !!!
Why?(By definition. Because the first multiplier number belonging to the interval from)