What are the skills for solving the difference problem?

Meaning: The difference multiple problem is to know the difference between two numbers and the multiple relationship between two numbers, and find the two numbers. Formula: Difference (Multiples of 1) = Decimal; Decimal Multiples = Large numbers.

1. Carefully understand the meaning of the topic and judge whether it is a sum or a difference problem. The general way to judge the "sum times problem" is to grasp the following key words: "harmony", "total", "who is the multiple", etc.

To judge the difference problem, you can grasp these few keywords to judge the "ratio." Many. Compare.

Few. How much is the difference", "who is several times who", etc.

2. Determine the "1 multiple", or "1 multiple", and then draw the line segment diagram according to the multiple relationship. A common way to determine "1 times" is to find keywords, and in general, the amount after "yes", "than", "occupy", and "equal" is "1 times". If two or more of these words appear in a question, then we usually refer to the smaller quantity as "1 fold".

The reason for this is simple, people usually like to do addition rather than subtraction, preferring to do multiplication rather than division. In addition, when drawing a line segment diagram, it is generally necessary to draw "1 times" first, and then draw other amounts. Try to represent the known conditions on the top of the ** segment diagram, which is more intuitive and easy to analyze and understand.

3. Through analysis, find the multiple relationship corresponding to "and" or "difference". Only by finding a one-to-one correspondence can the correct answer be solved. Generally, "and" corresponds to "multiple+1"; "Difference" corresponds to "multiple-1".

This is important. Of course, specific problems need to be analyzed on a case-by-case basis.

The techniques for solving the sum times problem are as follows:

Knowing the relationship between the sum of two numbers and the multiples of two numbers, and finding how much each of the two numbers is, we usually call the sum and times problem. When solving such application problems, it is necessary to draw a line segment diagram according to the conditions and problems given in the question, so that the quantitative relationship is clear at a glance, so as to find out the law of solving the problem and solve it correctly and quickly.

and times the formula of the problem:

Sum of two numbers (multiples of 1) = decimals.

Decimal Multiples = Large numbers.

Example] The master and apprentice process a total of 100 parts, and the number of parts processed by the master is 4 times that of the apprentice. How many parts do the master and apprentice each process?

Analysis of dry manuscript stool] The number of parts processed by the master is 4 times that of the apprentice, and we treat the parts processed by the apprentice as 1 copy, and the parts processed by the master are such 4 copies. The master and apprentice processed a total of 5 parts, exactly 100, dividing 100 by 5 is the amount of 1 part, that is, the number of parts processed by the apprentice, and then the number of parts processed by the master.

It can also be analyzed with a line diagram.

Answer] 100 5 20 (pcs).

20 4 80 (pcs) no brigade.

Answer: The master processes 80 pieces, and the apprentice processes 20 pieces.

Lecture 5: A, B, and C have a total of 95 yuan, A has 3 times the money of B, and B is 20 yuan less than C. How much is A, B, and C?

Solution: Treat B's money as 1 share, A's money has 3 shares, if C's money is subtracted from 20 yuan, C is also 1 share, total: 1+3+1=5 (shares).

At this time, the total number of money: 95-20 = 75 (yuan), b: 75 5 = 15 (yuan), a: 15 3 = 45 (yuan), c: 15 + 20 = 35 (yuan).

A: A has 45 yuan, B has 15 yuan, and C has 35 yuan.

Difference multiplier formula: the number with a smaller number = the difference between the two numbers (multiple-1).

Large number = decimal number + difference or: large number = decimal multiple.

The difference multiple problem refers to the fact that the relationship between the multiples of two numbers (usually two numbers) is known, and their difference is known, and the two numbers are found separately.

Solution: 1) Draw a line diagram according to the meaning of the question.

2) Find out the difference and multiple relationship between two numbers. In some questions, the relationship between difference and multiple is not directly given, so it is necessary to find the difference and multiple first; In some questions, the two numbers themselves do not satisfy the multiple relationship, and they need to be increased or decreased before the multiple relationship is satisfied.

3) Use formulas to solve.

and difference times formula.

1. The formula for the sum difference problem.

Sum difference) 2 large numbers.

and difference) 2 decimals.

2. And times the problem.

and (multiples of 1) decimals.

Decimal Multiples = Large numbers.

or with decimal large numbers).