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

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

Part One: Learning Objectives

1. Master the checking methods of three-digit addition and subtraction. (emphasis)

2. Understand the diversification of algorithms and use verification methods correctly and skillfully for verification. (difficulty)

Column vertical calculation.

400－66= 378－39=

Is it correct? PPT, part 2: Exploring new knowledge

Knowledge points: Checking methods for three-digit addition and subtraction

How many yuan should be paid? Is the saleswoman right?

I switched places and calculated it again, it was 256 yuan.

Subtract 118 from 256, which is exactly 138, which is correct.

Pay the salesperson 300 yuan and get 44 yuan back, right?

Answer: Pay the salesperson 300 yuan and get 44 yuan back, yes.

Knowledge refining

1. Calculation method for addition:

(1) Exchange the positions of the two addends and calculate again;

(2) Subtract one of the addends from the sum to see if the result is equal to the other addend.

2. Calculation method for subtraction:

(1) Use subtraction to check. Subtract the difference from the minuend to see if the result is equal to the minuend;

(2) Use addition to check. Add the subtrahend to the difference to see if the result is equal to the minuend.

Is the calculation correct? PPT, the third part: consolidation practice

1. (1) How much did it cost in total?

165＋117＝282(yuan)

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

300-282＝18 (yuan)

wrong.

2. Forest doctor.

3. Write the number directly.

600－230＝ 270＋190＝

180＋250＝ 200－150＝

420＋260＝ 570－280＝

700＋260＝ 450－200＝

4. A bottle of drink weighs 295 grams in total after drinking half of it. The bottle weighs 40 grams. How many grams does this bottle of drink weigh in total?

295-40＝255 (grams)

255＋255＝510(grams)

510+40=550 (g)

Answer: This bottle of drink weighs 550 grams in total.

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

What knowledge have you learned in this class?

1. Calculation method for addition:

(1) Exchange the positions of the two addends and calculate again;

(2) Subtract one of the addends from the sum to see if the result is equal to the other addend.

2. Calculation method for subtraction:

(1) Use subtraction to check. Subtract the difference from the minuend to see if the result is equal to the minuend;

(2) Use addition to check. Add the subtrahend to the difference to see if the result is equal to the minuend.

Is the calculation correct? PPT, Part 5: Homework

Assignment 1: Complete the exercises related to the textbook.

Assignment 2: Complete the corresponding exercises.

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:

"Is the Calculation Right?" 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..

"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..

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Update Time: 2024-10-03

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

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