The concept, properties and differences of 1
Difference is a mathematical operation symbol, which represents the result of subtraction of two numbers or algebraic expressions. The nature of difference is non-negative: the difference between two numbers or algebraic expressions is non-negative, that is, the difference is greater than or equal to zero. Law of addition and association: the difference or algebraic subtraction of any three numbers can be interchanged, that is, (a-b)-(c-d)=(a-c)-(b-d).
2. Difference calculation method
Direct calculation: according to the definition of difference, directly calculate the result of two numbers or algebraic subtraction. The calculation is carried out by using additive associative law and subtractive commutative law: by transforming the form of difference, the complex calculation is simplified to simple calculation. Using the nature of operation to calculate: through the nature of difference, complex calculation is simplified to simple calculation.
3. Application of differences
Find the value of algebraic expression: some items in algebraic expression are expressed by their reciprocal, and then subtracted, which can simplify the calculation. Solving the equation: When solving the equation, the equation can be converted into the difference between two algebraic expressions to simplify the calculation. Comparison size: By comparing the absolute value of the difference between two numbers, we can judge the size relationship between the two numbers.
Learn math skills well
1, cultivate mathematics interest and way of thinking
Feel the beauty of mathematics: discover the beauty of symmetry, abstraction and logic in mathematics, and stimulate the interest and love of mathematics. Cultivate thinking in images and abstract thinking: by solving mathematical problems, exercise the ability of thinking in images and abstract thinking. Cultivate innovative spirit: try to solve mathematical problems in different ways and cultivate innovative consciousness and mathematical thinking ability.
2. Establish a scientific learning method.
Make a reasonable study plan: define the study goal, plan and timetable, and allocate time reasonably. Multi-channel access to mathematical knowledge: not only textbooks, but also reference books and the Internet. Pay attention to exercise training: through a large number of exercises, strengthen the understanding and mastery of knowledge points, improve problem-solving ability and test-taking skills.
3. Cultivate good study habits and psychological quality.
Develop the habit of active learning: get rid of the attitude of passive learning and actively study, think and ask questions. Cultivate patience and perseverance: Mathematics learning needs patience and perseverance, and it needs to overcome difficulties and stick to it. Keep a positive attitude: keep a positive learning attitude, encourage yourself, believe in yourself, and don't give up easily when encountering difficulties.