1, answer fewer questions than Dobby: use fewer questions than Dobby, and skillfully use drawing to compare sizes. Use addition to calculate large numbers and subtraction to calculate decimals. If you find more or less, use subtraction to calculate.

2, less application problems than more, clever use of drawing than size.

3. Use addition to calculate large numbers and subtraction to calculate decimals.

4. If the requirement is more or less, it will be calculated by subtraction.

5. There are three kinds of problems:

6. Ask more questions first and ask less: for example, there are 39 Xiao Ming and 23 Xiao Hua. How many Xiao Hua is less than Xiao Ming? (Or how many cards does Xiao Ming have more than Xiao Hua? )

7. The second is to find a large number: for example, Xiaoming has 39 cards, Xiaohua has more 12 cards than Xiaoming, and how many cards does Xiaohua have?

8. The third is to find the smaller number: if Xiaoming has 39 cards, Xiaohua has fewer cards than Xiaoming 12. How many cards does Xiaohua have?

9. The key to solving the problem of finding a larger number and a smaller number is to get a larger number (large number) and a smaller number (decimal number) from the word "bi". You can learn who is older and who is younger by drawing, drawing line segments, stick figures and circles.

Expand knowledge:

First, ask a few more questions.

1, Xiaohong has 15 sweets, and Xiaoli has 10 sweets. How many sweets does Xiaohong have more than Xiaoli? Xiaohong has 15 sugar, and Xiaoli has 10 sugar. How many sweets is Xiaoli less than Xiaohong?

2. To solve this kind of problem, it is generally based on the last sentence in the formula, "More solutions and less solutions, subtraction can solve all the problems." You can solve the problem that Xiaohong is more than Xiaoli 15- 10=5 sweets; Xiaoli is less than Xiaohong 15- 10=5 sugars.

Second, find a large number and a decimal.

1. There are two ways to find a larger number. For example, Xiao Zhang has 29 apples, 8 fewer than the others. How many apples are there in Xiao Chen? Xiao Zhang has 29 apples, and Chen Xiao has 8 more than Xiao Ming. How many apples are there in Xiao Chen?

The problem-solving skill is the formula of "large numbers are solved by addition", that is, the method used in the example is addition, so parents can let their children try to solve by addition, and finally get the correct answer: Chen Xiao has 29+8=37 apples.

2. There are two commonly used expressions to solve decimals. For example, Chaochao has more money from 45 yuan than flowers 13 yuan. How much is the flower? Chaochao has 45 yuan's money, and the ratio of flowers to flowers is less than Chaochao 13 yuan. How much is the flower?

It uses the formula of "Decimal is calculated by subtraction" to solve the problem, in which both sum and sum need to solve a small number, that is, the amount of money spent. When parents instruct their children to do this kind of problem, they can ask them to solve it by subtraction according to the formula. The answer can be: 45- 13=32 yuan money.

More than less math problems is one of the key contents that children need to master in primary school. If children master the rules and skills, they can solve the related problems in homework or exams, and also lay a good foundation for learning more complex comprehensive application problems in junior and senior grades.