# Data Handling: Class 6 Maths NCERT Chapter 9

## Key Features of NCERT Material for Class 6 Maths Chapter 9 – Data Handling

In the last chapter 8 Decimals, we studied decimals, representation of decimals, applications and mathematical operation on decimals. In this chapter of NCERT class 6 maths: Data Handling, we will study ways to organize data and also learn about pictographs and bar graphs.

### Quick revision notes

In our everyday life, we see different sorts of tables which consist of numbers, figures, names, and so on. These tables give ‘data’. Data is a collection of numbers accumulated to give some information.

### Data and information

It is an assortment of numbers accumulated to give some data.

### Frequency

Frequency is the occasions a specific worth happens in the given data.

Eg: Marks scored by various understudies in a class: 1, 2, 2, 4, 3, 3.

### Recording Data

Sometimes information is required quickly. It is possible by adopting an apt system of gathering data.

Adopt some suitable systems for collecting data.

### Organizing data

• Data must be organized in a proper manner.
• This helps in getting clear information.
• Example: In a class, 25 students were asked to choose one fruit from Banana, Orange, Apple and Guava.
The following shows organized data:

### Pictograph

A pictograph shows information as pictures, items or parts of items. The image, for the most part, assists with understanding the information. It helps answer the inquiries on the information initially. Pictographs are frequently utilized by dailies and magazines to pull in the attention of the readers. Although, it requires some practice to comprehend the data given by a pictograph.

#### Interpretation of a Pictograph

Basically by watching a pictograph, one can respond to the related inquiries rapidly.

The quantity of strawberries eaten by a student in different months is demonstrated as follows.

Question: Find the number of apples eaten in January, February, March and April.

Solution: Here every image of strawberry speaks to two strawberries.

⇒ In January student ate 8 strawberries, in febraury, they ate 4 strawberries,

While in march they ate 2 strawberries and in April 12 strawberries.

So, the total number of strawberries eaten in all the four months is 30.

#### Drawing a Pictograph

We draw pictographs utilizing symbols to represent a number of things or items.

### A Bar Graph

Data representation through pictograph takes time and is a tedious process. So, ais another visual method of depicting information.

In a bar diagram or a bar graph, bars of uniform widths are raised evenly or vertically with equivalent spacing between them. The length of the bar gives the required data. It is easier for users to compare data and draw conclusions through a bar graph.

#### Interpretation of a bar graph

Investigating the bar graph; we can react to the related requests with no issue.

• Given beneath are the scores of students in science. Compute the total scored by B and D. Solution:

###  Sum of marks scored by B and D = 14 + 5 = 19

∴ The required sum is 19.

#### Drawing a Bar diagram

Firstly, we draw a horizontal line and a vertical line on the horizontal plane, we drawbars and on vertical lines, we write the numerals on the same. But we have to choose an appropriate scale. For instance, 1 unit =100 students. Good practice

### Questions

Question: The table gives the quantities of snacks ordered and the quantities of days as a tally. Find the frequency of snakes. Answer: From the frequency table the number of snacks requested between

• 2-4 for 4 days
• 4 to 6 for 3 days
• 6 to 8 for  9 days
• 8 to 10 for  9 days
• 10 to 12 for  7 days.

So the frequencies for all snacks requested are 4, 3, 9, 9, 7

Question: What is the ratio of the sales of branch B2 for the two years to the total deals of branch B4 for the two years?

Answer: From the graph, the consolidated frequencies of B2 and B4 are

B2 = 75 + 65 = 140

B4 = 88 + 95 = 180

In this manner, ratio=140:180 = 7:9

Question: What is the utilization of bar graphs?

Answer: We use bar graphs to compare quantities between various gatherings or track changes over a certain period of time. Furthermore, bar graphs are the most ideal choice when you are estimating change over some time, and when the progressions are bigger.

Question 3: Explain what is a simple bar graph?

Answer: A basic bar graph or outline is a diagram that we use to represent data including just a single variable arranged on a spatial, transient or quantitative basis. Moreover, in a simple bar diagram or graph, we make bars of equivalent width however their length shifts as indicated by the data.

September 5, 2020