"Is the calculation correct?" Addition and subtraction PPT

Description

"Is the calculation correct?" Addition and subtraction PPT

Part One: Learning Objectives

1. Be proficient in the operations of addition and subtraction.

2. Learn to correct errors in addition and subtraction and understand the causes of errors.

3. Be able to apply what you have learned to solve some simple practical problems.

[Key Points] Be proficient in addition and subtraction.

[Difficulty] Understand the reasons for errors in addition and subtraction and correct them.

Is the calculation correct? PPT, part 2: introduction of new knowledge

Talk about it, do the math, where is the mistake?

When borrowing continuously, one digit should be subtracted from the front.

Tell me, what are some good ways to reduce calculation errors?

Don't forget carry and carry.

Be careful and don't copy the wrong number.

forest doctor

Continuous borrowing does not decrease by 1.

Continuous borrowing does not decrease by 1.

The carry does not add 1.

Wrong addition question

234+256=480

296+153=431

515-49=474

900-632=368

Is the calculation correct? PPT, part 3: Classroom exercises

1. Fill it out

1. One addend is 780, the other addend is 130, and the sum of the two numbers is ( ).

2. Dad bought a computer for Xiao Ming. A computer cost 3,397 yuan. Dad paid 4,000 yuan and wanted to get ( ) yuan back.

2. Oral calculation

800-120= 480+60=

540+80= 840-50=

500+600= 370-280=

Teacher Li went to the store to buy sports equipment. The picture on the left is a breakdown of his purchase list.

(1) How much did it cost in total?

165+117=282 (yuan)

Answer: It cost 282 yuan in total.

(2) Teacher Li paid 300 yuan and got 28 yuan in change, right?

300-282=18 (yuan)

Answer: No, it should be 18 yuan.

Is the calculation correct? PPT, part 4: Class summary

Ways to reduce calculation errors:

1. Calculate according to the calculation rules;

2. When calculating, read the data clearly to avoid copying wrong numbers;

3. When calculating, don’t forget carry and carry;

4. Develop a good habit of checking calculations after calculation.

Is the calculation correct? PPT, Part 5: Classwork

1. Fill in ○ with ">", "<" or "=".

250+300○250+30 3800-800○3800+100

640-40○640-600 900-80○960-140

2. Fill in the blanks.

422+149=( )-149

665-279=( )+279

hint:

Minuend = Minuend + Difference

One addend = sum - another addend

3. Choose.

(1) 98 trees were planted in the second grade and 403 trees were planted in the sixth grade. Approximately ( ) trees were planted in the two grades.

A. 300 B. 400 C. 500

(2) ( ) is 198 more than 276.

A. 78 B. 474 C. 464

Keywords: Beijing Normal University Edition Second Grade Mathematics PPT Courseware Free Download, Is the Calculation Right PPT Download, Addition and Subtraction PPT Download, .PPT Format;

For more information about the PPT courseware "Are Additions and Subtractions Correct?", please click on the "Are Additions and Subtractions PPT Calculations Correct" PPT tab.

"Is the calculation correct?" Addition and subtraction PPT (Lesson 2):

"Is the Calculation Right?" Addition and Subtraction PPT (Lesson 2) Part One: Learning Objectives 1. Master the verification method of three-digit addition and subtraction. (Key points) 2. Correctly check three-digit addition and subtraction. (Difficulty) Calculate vertically. 294-177= 509+167= ... ... ... .....

"Is the calculation correct?" Addition and subtraction PPT (Lesson 1):

"Is the Calculation Right?" Addition and Subtraction PPT (Lesson 1) Part One: Learning Objectives 1. Master the verification method of three-digit addition and subtraction. (Key points) 2. Understand the diversification of algorithms and use verification methods correctly and skillfully for verification. (Difficulty) Calculate vertically. 40..

"Is the calculation correct?" Addition and subtraction PPT courseware:

Summary of the PPT courseware on addition and subtraction in "Is the Calculation Right?": 1. Use subtraction to check additions 2. Use sum to subtract any addend equal to another addend Summary: 1. Use subtraction to check addition 2. Use sum to subtract any addition The number is equal to another addend... ... Practice it..

File Info

Update Time: 2024-07-04

This template belongs to Mathematics courseware Beijing Normal University Edition Second Grade Mathematics Volume 2 industry PPT template

Preview