Multiplication is a basic mathematical operation, and its definition is to multiply two or more numerical values to get their products. The symbol of multiplication is "X", and the result of multiplication of two numbers is called product. For example, the number 5 multiplied by the number 3 can be expressed as 5×3= 15. In multiplication, we can decompose a number into the sum of several numbers, then multiply each decomposed number with another number, and finally add them to get the product. This is the so-called distribution law. For example, 7×(3+2) can be interpreted as (7×3)+(7×2)=35. Multiplication also follows the commutative law and associative law, which shows that products of the same number can be multiplied in different order to get the same result. For example, 2×3×4 can be written as 3×2×4 or 4×3×2, because both are equal to 24. Multiplication is widely used in various fields of mathematics, including algebra, geometry, calculus and so on. It is one of the important foundations of learning mathematics.