"Subtraction" Addition and subtraction within 100 PPT

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"Abdication and Subtraction" PPT on addition and subtraction within 100

Part One Content: Review Introduction

My mouth is the best.

16－8＝ 10－4＝ 15－7＝

11－6＝ 12－8＝ 10－5＝

Abdication minus PPT, Part 2: Scenario introduction

How many more gold medals does China have than the United States?

Try doing the math.

1 minus 6 is not enough to reduce the ones position, what should I do?

China has 51 coins and the United States has 36. How many more coins does China have than the United States?

51-36=

Is the single digit enough to reduce it? What if it’s not enough?

After stepping back from the tens place by 1, the tens place must be calculated as ( ) minus ( ).

Subtracting 4 from 0 in the ones digit is not enough. After retreating from the tens digit by 1, the ones digit must be calculated as ( ) minus ( ).

What should you pay attention to when doing subtraction calculations?

pen arithmetic subtraction

Same digit alignment;

Decrease from single digit;

If the ones digit is not reduced enough, step back 1 from the tens digit.

Abdicate and reduce PPT, the third part of the content: apply what you have learned

1. Do the math.

43－29＝ 72－27＝

61-3＝ 54-16＝

2. What is the tenth place difference between the following questions?

3. Is the following calculation correct? Correct what is wrong.

4. Can you fill it out?

5. On the sports field.

(1) How many more people play football than basketball?

44-26=18 (people)

(2) How many people are playing football and basketball?

44+26=70 (person)

Abdication minus PPT, Part 4: Summary

What knowledge have you learned?

Pen arithmetic subtraction also starts from the ones place.

1. The written calculation method of subtracting two digits from two digits:

①Align with the same digits;

②Decrease from the single digit;

③If the ones digit is not enough to subtract, retreat 1 from the tens digit, add 10 to the ones digit, and then subtract.

2. The algorithm of subtraction when the ones digit of the minuend is 0 is the same as the algorithm of subtraction when the ones digit of the minuend is not 0. If the units digit is not enough to subtract, the tens digit must be subtracted by 1, but because the ones digit of the minuend is not It is 0, and the ones digit after moving back 1 from the tens digit should be calculated as 10 minus a few.

Keywords: Free download of PPT courseware for second grade mathematics from the People's Education Press, download of subtraction PPT, download of addition and subtraction within 100 PPT, .PPT format;

For more information about the PPT courseware "Addition and Subtraction Within 100, Subtraction with Reduction", please click on the Addition and Subtraction within 100 PPT, Subtraction with Reduction PPT tag.

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Update Time: 2024-10-05

This template belongs to Mathematics courseware People's Education Press Second Grade Mathematics Volume 1 industry PPT template

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