For example, formulas can be divided into addition formulas, subtraction formulas, multiplication formulas, division formulas and formulas containing two or more operations.
In mathematics, formula refers to the formula listed in the calculation of numbers (or algebraic expressions), including numbers (or letters instead of numbers) and operation symbols (four operations, power, root, factorial, permutation and combination, etc. ). Unlike expressions, expressions are meaningful expressions that connect data of the same type (such as constants, variables, functions, etc.). ) Use operation symbols according to certain rules.
Elementary arithmetic order: when operating at the same level, it is calculated from left to right in turn; Two-stage operation, first multiply and then divide, then add and subtract. When there are brackets, count the inside of brackets first, and then count the outside of brackets; When there are multiple brackets, count the brackets first, then the brackets inside, then the braces inside, and finally the brackets outside. If there is a power, calculate the power first.
Multiplication is a simple operation of addition and division is a simple operation of subtraction. Subtraction and addition are reciprocal operations, and division and multiplication are reciprocal operations. When several addends are added, the positions of addends can be exchanged at will; Or add a few addends first and then add them with other addends, and the sum remains the same. Subtracting the sum of two numbers from a number is equivalent to subtracting each addend in the sum from this number in turn.
The concept of arithmetic:
Arithmetic is the oldest, most basic and primitive part of mathematics. It studies the properties and operations of numbers. The oldest mathematics, arithmetic, is formed by accumulating and sorting out the properties of numbers and the experience of four operations between numbers in the application process.
All mathematics in ancient times was called arithmetic, and modern algebra and number theory originally developed from arithmetic. Later, the concepts of arithmetic and mathematics appeared, which replaced the meaning of arithmetic and included all mathematics, and arithmetic became a branch of it.
The content of arithmetic includes two parts. The first part discusses the reading, writing and basic operations of natural numbers. This part includes carry system and numeration system, mainly decimal system. Other decimal systems and decimal systems only adopt different cardinality and can be calculated according to the principle and principle of decimal digits. Another part of arithmetic includes the application of arithmetic operation methods and principles.