Multiplication formula: factor x factor=product ÷ factor=factor.
Division formula: dividend ÷ divisor=quotient x divisor=dividend dividend ÷ quotient=divisor.
Multiplication and division algorithm:
1. In the same level operation, it is calculated from left to right.
2. In two-level operations, multiplication and division are performed first, and then addition and subtraction are performed.
3. When there are parentheses, the ones inside the parentheses are counted first, and then those outside the parentheses.
4. When there are multiple layers of parentheses, the ones inside the parentheses, the ones inside the brackets, the ones inside the braces, and the ones outside the brackets are calculated first.
Multiplication is a shortcut for adding up the same numbers. The operation result is called product, and "x" is the multiplication sign. The multiplication of integers (including negative numbers), rational numbers (fractions) and real numbers is defined by the system generalization of this basic definition.
Multiplication can also be seen as calculating the objects arranged in a rectangle (integer) or finding the area of a rectangle whose side length is given. The area of the rectangle does not depend on which side is measured first, which indicates the swap attribute. The product of the two measurements is a new type of measurement, for example, multiplying the lengths of two sides of a rectangle to give its area, which is the theme of dimensional analysis.
Division is one of the four operations. Given the product of two factors and one of the non-zero factors, the operation of finding the other factor is called division.
The division of two numbers is also called the ratio of two numbers. If ab=c (b ≠ 0), the operation of using the product c and the factor b to find another factor a is division. Write c ÷ b, read as c divided by b (or b divided by c). Where c is called the dividend, b is called the divisor, and the result of the operation a is called the quotient.