1. Arabic numerals: This is the most common number system, including numbers from 0 to 9. They are used to count, calculate and represent numerical values.
2. Superscript and Subscript: Superscript (such as x_) and Subscript (such as H_O) are used to represent the power sum coefficient. For example, "x_" means "the square of x" and "H_O" means water molecules.
3. Greek letters: Greek letters are often used in mathematics and science to represent specific concepts, such as π (π), α (angle), β (β) and so on.
4. Sum symbol: ∑(sigma) is used to represent the sum of a series of numbers. For example, "∑i= 1ni" means the sum of all integers from 1 to n.
5. Product symbol: ∏(pi) is used to represent the product of a series of numbers. For example, "∏i= 1ni" means the product of all integers from 1 to n.
6. Limit symbol: lim or→ is used to indicate the limit of a function at a certain point or near infinity.
7. Unequal symbols: ≥, ≤, ≦, ≈, etc. Used to indicate unequal or approximate relationships.
8. Root sign: √ is used to represent the square root and √ is used to represent the cube root.
9. Fractions and decimals: Fractions and decimals are used to represent parts or decimals.
10. factorial symbol:! Used to represent the factorial of a number, that is, the number multiplied by the product of all positive integers less than it.
The above are just some types and functions of digital symbols. In fact, there are many other symbols and symbols in mathematics, all of which have their own meanings and uses.