CBSE Maths Notes For Class 8 Chapter 4 Introduction to Data Handling

We come across many incidents in our day-to-day lives wherein we may be required to collect, classify, and draw conclusions from data that reach us. Data is the information that needs to be handled in an organised way. Data can be numbers, words, and even pictures. But gathering data is not the aim; we need to understand how to control them well to reach proper conclusions. 

For Example:

• The runs scored by Virat Kohli in the last 10 ODIs. 
• Marks scored by students in any subject in your class.

1.0CBSE Class 8 Maths Chapter 4 Data Handling - Revision Notes

How to Collect Data?

Data is collected in different forms like pictographs, graphs, double bar graphs, etc. 

Pictograph 

The pictorial representation of data is called Pictographs. Here is what it looks like, 

A Bar Graph 

In Maths, the graphical representation of data is in the form of a bar graph with constant height and width relevant to the value it represents.

Double Bar Graph: 

A bar graph showing 2 sets of data simultaneously. It is useful for comparing the data.

A Pie Chart 

A pie chart is just a circle divided into portions, like a pizza. Every portion of it shows what percentage or proportion each category or item makes up of the whole. The bigger the slice of the circle, the bigger the share.

How to Draw a Pie Chart?

Let’s Understand, with the help of an example, how to make a pie chart. 

Example: Draw a pie chart for the given data. The data shows the preference of students of a school in terms of percentage in different formats of cricket. 

Solution: 

1. Draw a circle of any radius according to your preference. 
2. Find the angle associated with the given percentage of data by the following formula: 

$\text{ Angle }=\frac{\text{ Given percentage }}{100}\times 360$

3. Draw each section using a protractor. 
4. Continue till done. 

For the given example, 

Chance and Probability 

Chances are the likelihood of an event occurring. For example, when you toss a coin, there is a chance that it will fall either head or tail. Let’s look at another example. Say you bring a raincoat every day, but by chance, one day you forget your raincoat and that day it starts raining heavily.

Probability is how we measure the likelihood of an event happening in Maths. A number between 0 and 1, where 0 indicates that the event cannot happen and one is certain to occur. The higher the probability, the more likely it is to occur. Probability helps us understand and predict many events in everyday life, such as weather, games, and so much more. 

Random Outcome 

You might have noticed when two captains of cricket teams come out for a toss to decide who will bat or ball first. It is decided on Haid or Tail. In Maths, this type of experiment is called a random experiment, and the event is called a random outcome.  

Equally Likely Outcome 

The equally likely outcomes are when every possible result has a similar chance of happening. We use tally marks to collect these events. 

Calculation of Probability 

A probability solution is defined as the process of finding the likelihood or the chance of an event happening. Therefore, the calculation of probability by the formula: 

$\text{ Probability }=\frac{\text{ No.of favorable events }}{\text{ Total No.of Events }}$

Example: Manish throws a dice once. Find the probability of the event that the dice shows a multiple of 2.

Solution: Total no. of events = 6 

No. of Favorable events = 3 (Multiple of 2 in dice are 2,4,6; hence, there are three chances of getting multiple of 2) 

Probability = $\frac{3}{6}=\frac{1}{2}$

2.0Key Features of CBSE Math Notes for Class 8 Chapter 4

• Visual aid is provided to get a clear understanding of the concepts related to Data handling. 
• Clear and easy explanations of various concepts make these notes ideal for self-study. 
• Our highly experienced faculty carefully checks and analyses notes to ensure their accuracy.