1, algorithm

When the plus sign is in front of the bracket, the bracket is removed, and the formula in the bracket remains unchanged; When there is a minus sign in front of the bracket, remove the bracket, and the plus sign in the bracket becomes a minus sign, and the minus sign becomes a plus sign; When the plus sign is in front of the bracket, the bracket is removed, and the formula in the bracket remains unchanged; When the minus sign comes before the parentheses, remove the parentheses, and the plus sign in the parentheses becomes a minus sign, and the minus sign becomes a plus sign.

2. Definition of multiplication

Multiplication is a shortcut to add up the same numbers. The result of its operation is called product, and "X" is the symbol of multiplication. From the philosophical point of view, multiplication is the result of qualitative change caused by additive quantity. The multiplication of integers (including negative numbers), rational numbers (fractions) and real numbers is a systematic summary of this basic definition.

3. Definition of division

Division is one of the four operations. Division of two numbers is also called the ratio of two numbers. How many digits is the divisor? Look at the first few digits of the divisor first. If the first few are not enough, look at one more. Except for the one to which they belong, all the vendors will write on it, which is not enough for the quotient of one and zero.

The remainder is less than the divisor. If the quotient is decimal, the decimal point of the quotient should be aligned with that of the dividend. If the divisor is a decimal, it must be divided into integers and then calculated.

Matters needing attention in doing math problems:

1, check the problem carefully.

After getting the math test paper, candidates should first read through the whole volume and have a thorough understanding of the questions. One is to see how many topics there are and whether there are typographical errors. The other is to have a general understanding of the difficulty of the whole paper, so that you can know fairly well and estimate the time allocation for answering questions.

2, the operation speed is faster

Don't make a mountain out of a molehill, especially multiple-choice questions and fill-in-the-blank questions. You have to understand that our ultimate goal is to choose the right answer or write the final answer, without a detailed process, so we don't need to write a big question.

3, must: review, training.

Every time you do several sets of math problems, you need to go back and summarize which knowledge points, chapters and questions you are prone to, analyze the reasons and formulate countermeasures. If several sets of questions always have problems on one knowledge point, we must carry out special training to change knowledge points and questions in order to make a breakthrough.