1, multiplication and addition and subtraction: multiplication is an advanced operation, which involves finding the power of a number. The order of power operation is from high to low, that is to say, high power operation is carried out first, and then low power operation is carried out. The order of addition and subtraction is also from left to right, that is to say, first add and subtract on the left and then add and subtract on the right.
2. Multiplication and division operation: the order of multiplication and division operation is from left to right, that is, the multiplication and division operation on the left is performed first, and then the multiplication and division operation on the right is performed. In the same level of operation, the priority of multiplication and division operations is the same, so it is necessary to decide the operation order according to parentheses.
3. Parentheses: When an expression contains parentheses, we need to calculate the expression in parentheses first. When calculating the expressions in parentheses, you also need to follow the same operation order. In the mixed operation of rational numbers, we need to follow the operation rules and algorithms.
The Application of Rational Numbers in Mathematics
1, rational numbers are widely used in arithmetic. Basic operations such as addition, subtraction, multiplication and division can be easily performed within the range of rational numbers. By introducing fractions, some quantities can be expressed more accurately, so as to better understand and calculate various problems in life, such as addition, subtraction, multiplication and division of fractions, four operations of decimals and so on.
2. Rational numbers also play an important role in algebra. By defining variables and equations, we can express various mathematical relationships and make inferences. The solutions of these algebraic equations can be rational numbers or more complex mathematical forms, but rational numbers always play a key role in them.
3. Rational numbers also have important applications in geometry and trigonometry. For example, we can use rational numbers to measure angles and lengths, so as to construct and analyze figures in Euclidean geometry. In trigonometry, we can use rational numbers to define and calculate various angles and lengths.