The arithmetic square root of radical number four is 2. Any non-negative number has an arithmetic square root. According to the relationship between power operation and root operation, the square of a non-negative number is used to calculate the arithmetic square root of the number. Find the arithmetic square root of 16, and think: Which square of positive number is equal to 16, it is easy to think that the square of 4 is equal to 16, so the arithmetic square root of 16 is equal to 4.

Significance and nature of radical sign

The root sign is the symbol of mathematical square root operation. The meaning of the root sign is a symbol used to represent the root operation of a number or an algebra. If the n power of A =b, then A is the n power square root of B or A is the 1/n power of B. Different root numbers will appear, such as finding the square root of a number, adding the positive and negative root numbers, finding the arithmetic square root of a number, adding a root number, finding the cube root of a number and adding a cube root. Different radicals have different properties.