RS Aggarwal Solutions Class 8 Chapter-21 Data Handling (Ex 21A) Exercise 21.1 - Free PDF
FAQs on RS Aggarwal Solutions Class 8 Chapter-21 Data Handling (Ex 21A) Exercise 21.1
1. What key skills will I master by using the RS Aggarwal Solutions for Class 8 Maths Chapter 21, Exercise 21A?
By following the step-by-step solutions for Exercise 21A, you will master the fundamental skill of organising raw data. You will learn the correct procedure to construct a frequency distribution table, which includes determining the range, creating appropriate class intervals, using tally marks accurately, and recording the frequency for each class. This is a foundational skill for all further topics in data handling.
2. What is the correct method to construct a frequency distribution table for the questions in Exercise 21A?
The correct method, as demonstrated in the solutions, involves a few key steps:
First, identify the highest and lowest values in the given dataset to find the range.
Next, decide on a suitable number of class intervals (or groups) that cover the entire range of data. Ensure the classes do not overlap.
Go through the dataset and assign a tally mark for each data point in its corresponding class interval.
Finally, count the tally marks for each class to find the frequency and record it in the table.
3. Why is it crucial to correctly determine the 'range' of the data before creating class intervals in Exercise 21A?
Determining the range (the difference between the highest and lowest observation) is a critical first step because it helps you decide the span of your data. This information is essential for choosing a logical class size and the number of class intervals. An incorrect range can lead to class intervals that are too broad or too narrow, making the final frequency table less effective at showing patterns in the data.
4. What are some common mistakes to avoid when solving problems from RS Aggarwal Class 8 Chapter 21, Exercise 21A?
When working on Exercise 21A, students should be careful to avoid these common errors:
Incorrect Tally Counting: Miscounting or misplacing tally marks, especially with larger datasets.
Overlapping Class Intervals: For example, using intervals like 10-20 and 20-30. A value of 20 would fit in both, which is incorrect. Use non-overlapping intervals like 10-19 and 20-29 or exclusive intervals like 10-20 and 20-30 where the upper limit is excluded.
Forgetting a Data Point: Accidentally skipping a number while tabulating it.
Calculation Errors: Making simple mistakes while finding the range or counting frequencies.
5. How does creating a frequency distribution table in Ex 21A make raw data more understandable?
A frequency distribution table transforms a chaotic list of raw numbers into a structured and meaningful summary. Instead of looking at dozens of individual figures, the table groups the data into classes and shows how many data points fall into each group. This immediately helps in understanding the data's distribution, identifying which values occur most or least often, and spotting patterns that are impossible to see in the unorganised raw data.
6. What is the specific role of 'tally marks' in the solutions for Data Handling Exercise 21A?
Tally marks serve as a systematic and real-time counting tool. When dealing with a list of observations, it is very easy to lose track or double-count. Tally marks provide a foolproof method to record each observation as you encounter it. The practice of grouping them in sets of five (four vertical lines and one diagonal slash) makes the final counting of the frequency for each class interval quicker and less prone to errors.
7. Are the problem-solving methods in these RS Aggarwal solutions aligned with the CBSE 2025-26 syllabus?
Yes, the methods for data organisation and construction of frequency distribution tables provided in the solutions for RS Aggarwal Class 8 Chapter 21 are fully compliant with the latest CBSE curriculum guidelines for the 2025-26 academic year. Following these solutions ensures that you are preparing with the correct methodology expected in your school examinations.











