"Algebraic Expressions" Integers and their addition and subtraction PPT download (Lesson 1)

Description

"Algebraic Expressions" Integers and their addition and subtraction PPT download (Lesson 1)

Part One: Learning Objectives

1. Understand the concept of algebraic expressions and be able to use algebraic expressions to express quantitative relationships in simple problems; (difficulty)

2. In specific situations, be able to find the value of algebraic expressions and explain its practical significance. (emphasis)

Algebraic PPT, part 2: introducing new lessons

This summer vacation, the teacher set off from Shenzhen and traveled to Beijing with a tour group. Although he was fully prepared, he still encountered many mathematical problems. I hope everyone can help the teacher!

Tour 1: Preparation

The temperature in Shenzhen is x degrees Celsius. The temperature in Beijing is 4 degrees Celsius lower than that in Shenzhen. The temperature in Beijing is ______ degrees Celsius.

Tour 2: Departure

The distance from Shenzhen to Beijing is s kilometers. The speed of the high-speed rail is 300 kilometers/hour. It takes ______ hours to reach Beijing.

Tour 3: Buy tickets

We have a adult and b students. We need to pay ________ yuan for tickets.

Algebraic PPT, Part 3: Teaching new lessons

The concept of algebraic expressions

concept learning

The formulas like these are all formed by connecting numbers and letters using operational symbols, and are called algebraic formulas.

(Arithmetic symbols include +, -, ×, ÷, and power)

Column algebraic expressions based on actual problems

Example 3 (1) The water speed of a river is 2.5 km/h, and the speed of the boat in still water is v km/h. Use the formula to express the speed of the boat when traveling along the current and against the current in the river;

Analysis: When traveling along the current, the speed of the boat = the speed of the boat in still water + the speed of the water flow;

When traveling against the current, the speed of the boat = the speed of the boat in still water - the speed of the water flow.

(2) It costs x yuan to buy a basketball, y yuan to buy a volleyball, and z yuan to buy a football. Use the formula to express the total amount of money needed to buy 3 basketballs, 5 volleyballs, and 2 footballs;

(3) As shown in the picture below on the left (unit of length in the picture: cm), use the formula to express the area of ​​the triangle ruler;

(4) Right The picture below is the building plan of a house (the length unit in the picture is m). The building area of ​​the house is expressed by an equation.

induction:

Column key points:

① Grasp key words and clarify their meanings and the relationships between them, such as sum, difference, product, quotient, large, small, more, less, multiples, points, reciprocals, opposites, etc.;

② Clarify the statement hierarchy and clarify the order of operations;

③Keep in mind some concepts and formulas.

Algebra PPT, Part 4: Practice in class

1. Express the following quantities using formulas

(1) 5 boxes of apples weigh m kg, and each box weighs _______kg;

(2) If a number is 5 less than 2 times a, then the number is _______;

(3) The total number of students in the school is x, of which girls account for 52%, then the number of girls is _______ and the number of boys is _______;

(4) There is a student in a class, and a batch of books is distributed to the whole class for reading. If each student is given 4 books, and there are still 25 books missing, then this batch of books totals _______ books;

2. Determine which of the following expressions are algebraic and which are not?

3. The ticket price of a certain park is: 10 yuan/ticket for adults; 5 yuan/ticket for students.

(1) A tour group has x adults and y students. How much ticket fee should the tour group pay?

(2) If the tour group has 37 adults and 15 students, how much ticket fees should they pay?

4. Modern nutritionists use the body mass index to measure the degree of fatness and thinness of the human body. This index is equal to the quotient of the human body mass (kilograms) and the human body height (meters) squared. For adults, the body mass index is between 20 and 25, and the weight Moderate; a body mass index below 18 is underweight; a body mass index above 30 is overweight.

Algebraic PPT, Part 5: Class Summary

algebraic expression

The concept of algebraic expressions

Requirements for writing algebraic expressions

discriminant algebra

Column algebraic expressions based on actual problems

Explain the actual meaning of algebraic expressions

Keywords: Free download of Beijing Normal University Edition seventh-grade mathematics PPT courseware for volume 1, algebraic formula PPT download, integer expressions and their addition and subtraction PPT download, .PPT format;

For more information about the PPT courseware "Integers and their addition and subtraction algebraic expressions", please click the PPT tab of "Integers and their addition and subtraction algebraic expressions".

"Algebraic Expressions" Integers and their addition and subtraction PPT download (Lesson 2):

"Algebraic Expressions" Integral Expressions and Their Addition and Subtraction PPT Download (Lesson 2) Part One: Learning Objectives 1. Be able to find the value of algebraic expressions and explain the actual meaning of the values ​​of algebraic expressions. (Key Points) 2. Use algebraic expressions to evaluate and infer the values ​​reflected by algebraic expressions Rules. (Difficulty) ... ... ....

"Algebraic Formulas" Integral formulas and their addition and subtraction PPT download:

"Algebraic Expressions" Integral Formulas and Their Addition and Subtraction PPT Download Part One: Review In the last lesson, we used matchsticks to put together the square as shown in the picture. The quantitative relationship between the number of squares and the number of matchsticks used was found, and letters were introduced, that is, using letters...

"Algebraic Formulas" Integral formulas and their addition and subtraction PPT (Lesson 2):

"Algebraic Expressions" Integer expressions and their addition and subtraction PPT (Lesson 2) Part 1 content: Knowledge points Basic knowledge point 1 Substitute directly to find the value of the algebraic expression 1. When m=2, the value of the algebraic expression 1/2 (m+8) is equal to ( A ) A.5 B.4 C.3 D.2 2. When a=-1b=2/5c=2, find the algebraic expression..

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Update Time: 2024-06-29

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