"Happy Farm" PPT courseware 6

Description

"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?

What mathematical information do you know from the picture?

What questions can you ask based on this information?

2. Cooperation and exploration

How many kilograms of flower soil 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?

(2×25)×20 =2×(25×20)

(5×8)×10 =5×(8×10)

To multiply three numbers, you can multiply the first two numbers and then the third number, or you can multiply the last two numbers and then the first number. The result will be equal.

Is this a rule?

Can you verify it with an example?

To multiply three numbers, first multiply the first two numbers and then multiply them by the third number;

Or multiply the last two numbers first, and then multiply them by the first number, and the product remains unchanged. This law is the associative law of multiplication.

Can you use letters?

(� ·b)·c = �· (b·c)

3. Independent practice

1. Tell me, what arithmetic laws are used in each of the following questions?

(1) 4×(15×3) = (4×15)×3

(2) (3×4) ×5 ×6 = 3× (4×5) ×6

(3) 125×(7×8) = (125×8)×7

2. Fill in the appropriate numbers or letters in □.

3. Fill in ○ with “＞”, “＜” or “=".

(1) 7×18×5○7× (18×5)

(2)125×(15×28)○(125×15)×38

(3) 234×56○56×234

(4) 105×10×99○105×9×99

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"Happy Farm" PPT courseware 7:

"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?

Based on this information, you can...

"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: 2024-10-03

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

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