The writing of 1. symbol should be clear and standardized to avoid ambiguity or confusion.

2. The case of symbols should be consistent, such as "X" and "X" indicating different concepts.

3. The position of the symbol should be accurate, ensuring that there is no extra space between the symbol and the number.

4. The use of symbols should conform to mathematical conventions and standards, and avoid individuals creating symbols at will.

5. In the expression, the multiplication symbol is represented by "x" or "."The division symbol is represented by "∫" and cannot be replaced by other symbols.

6. The fractional line "/"should be used instead of the diagonal line "/"or other symbols.

7. In sum and quadrature operations, correct symbols should be used, such as σ (sum) and π (quadrature).

8. Correct limit symbols and integral symbols should be used in calculus, such as lim (limit) and ∫ (integral).

9. In matrix operation, correct matrix symbols should be used, such as ∑ (sum), ∏ (quadrature) and _ (transpose).

10. In the function relationship, correct function symbols should be used, such as f(x) to indicate the relationship between function f and independent variable X.

1 1. In derivative and integral, correct derivative symbols and integral symbols should be used, such as' (derivative) and _ (integral).

12. Correct probability symbols should be used in probability theory, such as P (probability) and C (combination).

13. When using special symbols, pay attention to their meanings and conditions of use to avoid misunderstanding or mistakes.

14. In mathematical formulas, attention should be paid to aligning symbols and numbers to make the formula structure clear and readable.

15. In mathematical papers or reports, corresponding format requirements should be followed, including the use of symbols.

In a word, the use rules and precautions of mathematical symbols are the basis to ensure the accuracy, clarity and standardization of mathematical expressions. Abiding by these rules can improve the efficiency and accuracy of mathematical communication.