"Happy Farm" PPT courseware 7

Description

"Happy Farm" PPT courseware 7

1. Situation introduction

There are 56 hollies, 72 willows and 28 poplars.

How many saplings were purchased in total?

There are 80 roses, 88 peonies and 112 camellias.

How many flower seedlings did you purchase in total?

What questions can you ask based on this information?

What mathematical information do you know from the picture?

2. Cooperation and exploration

How many saplings were purchased in total?

Think about it:

1. To solve this problem, what can you ask for first and what can you ask for next?

2. Can you provide comprehensive calculation solutions?

Observe the following two sets of calculations, what do you find?

(56+72)+28 =56+ (72+28)

(80+88)+112 =80+ (88+112)

To add three numbers, add the first two numbers first, or add the last two numbers first, and the sum remains unchanged.

Is this a rule?

Can you verify it with an example?

To add three numbers, first add the first two numbers, and then add them to the third number;

Or add the last two numbers first, and then add them to the first number, and the product remains unchanged. This law is the law of additive associativity.

Can you use letters?

(�+b)+c＝�+(b+c)

When two numbers are added, the positions of the addends are swapped, and the sum remains unchanged. This law is the commutative law of addition.

Can you use letters?

�+b �b+�

3. Independent practice

1. Which arithmetic laws are used in the following calculations.

85+0 = 0+85 Commutative law of addition

47 + (33 + 8) = (47 + 33) + 8 additive associative law

(94+68)+32 = 94+ (68+32) additive associative law

75+(48+25)=(75+25)+48 Commutative law of addition Associative law of addition

2. Compare and take a look.

(1)8 7 6 1 5 0

+ 1 5 0 + 8 7 6 using the addition ( ) law

(2) 7+9 = (6+1) +9 =6+ (1+9) using the addition ( ) law

(3) 6+7+4 = 7+ (6+4) = 17 using the addition ( ) law

Calculation using the "make up ten method" can make the calculation simple.

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For more information about the "Happy Farm" PPT courseware, please click on the "Happy Farm ppt" tab.

"Happy Farm" PPT courseware 6:

"Happy Farm" PPT courseware 6

1. Situation introduction

Purchased 20 bags of flower soil, 25 bags per bag, 2 kilograms per bag.

How many kilograms of flower soil were purchased in total?

Purchased 10 bags of flower fertilizer, 8 bags per bag, 5 kilograms per bag.

How many kilograms of flower fertilizer were purchased in total? ..

"Happy Farm" PPT courseware 5:

"Happy Farm" PPT courseware 5

Class goals:

1. In the process of solving problems, discover and understand the distributive law of multiplication through mathematical activities such as observation, conjecture, verification, induction, and reasoning. (emphasis)

2. Be able to flexibly use the distributive law of multiplication to simplify...

"Happy Farm" PPT courseware 4:

"Happy Farm" PPT courseware 4

1. Situation introduction

Each bookshelf has 6 levels. There are an average of 125 books per floor.

There are 8 bookshelves.

How many books are there in this library?

What questions can you ask based on this information?

2. Cooperation and exploration...

File Info

Update Time: 2024-11-14

This template belongs to Mathematics courseware Qingdao Edition Fourth Grade Mathematics Volume 2 industry PPT template

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