# CBSE Class 7 Maths Revision Notes Chapter 3

## CBSE Class 7 Mathematics Revision Notes Chapter 3 – Data Handling

The Class 7 Mathematics Chapter 3 Notes are designed in a way so that students can understand the basic and advanced concepts of the topic clearly. The experts use simplified and accessible language to construct the topics included in the CBSE revision notesStudents can rely on the notes as they are created according to the latest CBSE guidelines and CBSE syllabus. Extramarks recommends that candidates should refer to the NCERT books and revision notes to score good marks in the final examinations. Candidates can also access study materials such as CBSE previous year question papers, CBSE sample papers, CBSE extra questions, including many more from Extramarks.

## Notes On Data Handling

• Double bar graph: It is considered a reliable tool to compare and contrast different values of two particular quantities, having the same observation.

For example: If in a class 6 students have scored well in mathematics and science. So through a double bar graph, we can analyze the performance of each student.

• Averages:

An average or mean of a data set can be found with addition of all the numbers given in the data set and then dividing the sum by the number of values in a data set.

The formula for arithmetic mean and range is as follows:

Mean = sum of all observations / total number of observations

• Median:

If the given data is arranged specifically in descending or ascending order, then the observation present in the middle has termed the median of that particular data.

Example: Suppose a group of people have a different number of apples: 10, 15, 20, 30, 25, 40, 35

Now the observation in ascending order will be: 10, 15, 20, 25, 30, 35, 40

Hence, the median value in this scenario will be 25 as it is the middle term.

• Mode:

The term that can get repeated most of the time in a given observation is known as a mode.

Example: Suppose a given set of numbers is 2,2,2,9,9,6,7,5

So the mode of this sequence is 2, as it is getting repeated most of the time.

• Probability

The chance of the occurrence of any particular event or incidence is known as probability.

The set of all the possible outcomes that can occur for a particular event is known as sample space.

Example: Experiment: Tossing of coin, sample space (S) = {H, T}

### Importance of Extramarks Revision Notes

The Class 7 Mathematics Revision Notes Chapter 3 are designed for students preparing for their final examinations. All the information added in the notes is collected by the experts from NCERT books. Extramarks recommends that candidates should study the CBSE revision notes for exam preparation. In addition, they can also access study materials such as CBSE sample papers, CBSE previous year question papers, CBSE extra questions, and important questions, among many more, through the platform.

The most important topics covered in the Class 7 Mathematics Chapter 3 Notes are given below.

1. Chance and probability -In case of a chance, the occurrence of any event is a rare prediction wherein its happening is not sure. However, probability is a measurement. In this, there are probable chances of an event.
2. Use of bar graphs for different purposes – Bar charts or Bar Graphs is a way to present the data in a visual format for recognising trends or patterns.
3. Median – Median refers to the middle value which is obtained when the data set is arranged from lowest to greatest number.
4. Mode – The number that is repeated or occurs the most number of times in a data set is mode.
5. Range – The difference between greatest value and lowest value in a data set is called as Range.
6. Arithmetic mean – The ratio of the sum of all the given observations to total number of observations given in a data set is termed as arithmetic mean.
7. Representation values – The number that is closest or nearest to the real value of the measurement is called representation values.
8. Organisation of data – In this, first the raw data is organised, then it is classified in different categories. This process is called Data Organization.
9. Collecting data – In data collection, information is gathered and measured on variables of interest. This helps in answering the research questions, in testing hypothesis and then evaluating the outcomes. This process is called data collection.
10. Introduction to data handling – This refers to the process of understanding about the data and thereafter handling it. In this, data is collected and then is presented in different forms.

The Class 7 Chapter 3 Mathematics Notes can help the student with a quick revision of the key concepts. It can help the candidates to get better clarity on the type of questions asked in the examination.

### 1. List all the topics covered in Chapter 3 Mathematics Class 7 Notes.

The Class 7 Mathematics Chapter 3 Notes cover all the important questions and topics required to score well in the final examination. A detailed list of the most significant topics is given below.

• Chance and probability
• Use of bar graphs with different purposes
• Median
• Mode
• Range
• Arithmetic mean
• Representation of values
• The organization of data
• Collecting data
• Introduction to data handling

### 2. What is the median according to the topics covered in Class 7 Mathematics Notes Chapter 3?

The median is defined as data organized in ascending order, from the smallest digital to the largest.The middle term in the ascending order organization of the data is known as the median of the given data.