1. Integer addition and subtraction operation: Error-prone places include the handling of symbols, carry and borrow.

2. Addition and subtraction of scores: error-prone, including the handling of different denominators, general and approximate scores, etc.

3. Decimal addition and subtraction: Error-prone places include decimal point alignment, carry and borrow processing, etc.

4. Multiplication and division operations: error-prone places include the memory of multiplication formula table, the remainder processing of division, etc.

5. Calculation of square root and cube root: The error-prone places include symbolic processing of roots, selection of results, etc.

6. Algebraic operation: The error-prone places include the simplification of algebraic expressions and the handling of merging similar items.

7. The nature and calculation of geometric figures: there are angle calculation and perimeter calculation that are easy to make mistakes.

8. Data collection and arrangement: error-prone places include data classification and drawing statistical charts.

9. Probability statistics: The error-prone places include the calculation of probability and the analysis of statistical charts.

These are just some common mistakes. In fact, there are many other knowledge points that are easy to make mistakes. In order to avoid these mistakes, students need to review carefully, understand concepts, do more exercises and correct them in time. At the same time, teachers should also pay attention to explain and emphasize these error-prone points in the teaching process to help students avoid making mistakes.