When calculating the addition of 9 by the method of "ten times ten", 9 is added to 10 and needs 1, and then the smaller number is divided into 1 and several, and the addition of 10 is more than ten.
2, 8, 7, 6 plus several calculation methods: (1) points; (2) the next number; (3) Add up to ten methods. Can be "large number division, decimal rounding" or "decimal division, large number rounding".
3, 5, 4, 3, 2 plus several calculation methods: (1) "large number division, decimal rounding". (2) "Decimal split, large number rounded".
Step 4 solve the problem
(1) When solving a problem, we can observe and analyze it from different angles, so as to find different ways to solve the problem.
(2) The practical problem of finding the total is calculated by addition.
The knack of mathematics learning method
Treat exams correctly.
First of all, we should focus on basic knowledge, basic skills and basic methods, because most of the exams are basic topics. For those difficult and comprehensive topics, we should seriously think about them, try our best to sort them out, and then summarize them after finishing the questions. Adjust your mentality, let yourself calm down at any time, think in an orderly way, and overcome impetuous emotions. In particular, we should have confidence in ourselves and always encourage ourselves. No one can beat me except yourself. If you don't beat yourself, no one can beat my pride.
Be prepared before the exam, practice routine questions, spread your own ideas, and avoid improving the speed of solving problems on the premise of ensuring the correct rate before the exam. For some easy basic questions, you should have a 12 grasp and get full marks; For some difficult questions, you should also try to score, learn to score hard in the exam, and make your level normal or even extraordinary.
Explore concepts and formulas carefully
Many students pay insufficient attention to concepts and formulas. This problem is reflected in three aspects: first, the understanding of the concept only stays on the surface of the text, and the special situation of the concept is not paid enough attention. For example, in the concept of algebraic expression (an expression expressed by letters or numbers is algebraic expression), many students ignore that "a single letter or number is also algebraic expression".
Second, concepts and formulas are blindly memorized and have nothing to do with practical topics. The knowledge learned in this way can't be well connected with solving problems. Third, some students do not pay attention to the memory of mathematical formulas. Memory is the basis of understanding. If you can't memorize the formula, how can you skillfully use it in the topic?
Our suggestions are: be more careful (observe special cases), go deeper (know the common test sites in the topic), and be more skilled (we can use it freely no matter what it looks like).
Polynomial definition
Mathematically, polynomial refers to the expression obtained by addition, subtraction, multiplication and power operation (non-negative integer power) of variables and coefficients.
More broadly, the sum of 1 or 0 monomials is also a polynomial. According to this definition, polynomials are algebraic expressions. In fact, there is no theorem that is valid only for narrow polynomials but not for monomials. When 0 is a polynomial, the degree is defined as negative infinity (or 0). Monomial and polynomial are collectively called algebraic expressions.