There are some common mistakes that students should avoid while appearing for CBSE Class 2 Mathematics exams. These mistakes can often lead to lower marks and can be easily avoided with proper preparation and awareness. Let's discuss these mistakes in detail:

1. Not understanding the concepts:
- It is vital for students to have a clear understanding of the basic concepts taught in class. Without a strong foundation, it becomes difficult to solve complex problems.
- Students should pay attention in class, take notes, and clarify their doubts with the teacher to ensure they have a thorough understanding of the topics.

2. Lack of practice:
- Mathematics requires regular practice to excel. Many students make the mistake of not practicing enough, especially solving different types of problems.
- Students should solve various exercises and practice questions from textbooks or study materials to strengthen their problem-solving skills.

3. Skipping steps:
- In mathematics, it is important to show all the steps involved in solving a problem. Skipping steps or not showing the complete solution can lead to a loss of marks.
- Students should ensure that they write each step clearly and label their answers appropriately.

4. Incorrect calculations:
- Making calculation errors is a common mistake that can be avoided with careful attention and practice.
- Students should double-check their calculations, especially while performing arithmetic operations like addition, subtraction, multiplication, and division.

5. Not managing time effectively:
- Time management is crucial during exams. Many students rush through the questions and make careless mistakes.
- Students should allocate time to each question based on its difficulty level and try to complete the paper within the given time frame.

6. Not reading the question properly:
- Sometimes, students misinterpret the question and provide incorrect answers. It is important to read the question carefully and understand what is being asked.
- Students should underline or highlight the important information in the question to avoid confusion.

7. Not revising:
- Revision plays a vital role in retaining concepts and formulas in memory. Many students neglect revision and end up forgetting important information during the exam.
- Students should revise regularly, create summary notes, and solve previous year's question papers to enhance their understanding and retention.

In conclusion, by avoiding these common mistakes, students can improve their performance in CBSE Class 2 Mathematics exams. It is crucial to have a strong conceptual understanding, practice regularly, show all the steps, perform accurate calculations, manage time effectively, read the questions carefully, and revise thoroughly.