# NCERT Class 6 Math՚S Chapter 9: Data Handling: Types of Data

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## Questions?

1. How to select the scale for bar chart?

2. When to draw bar chart?

3. What is the difference between histogram and bar chart?

## Data

Consider the data on the height of each of the class students.

## Statistics

Using this statistics, we can either plot it (as we will do later) or we can ask questions about data (interpret it)

## Types of Data

Consider the data on the fruit preferred by each of the class students.

## Concept of Frequency

• We start with subtraction - If I have apples and you take 3 from me, then I am left with 2 apples: 5 - 3 = 2.
• The value zero now becomes very important because I know that if I have 5 apples and you take away 5 apples then I am left with none, 0: that is 5 − 5 = 0

## Tally Marks- Number of Books

Now we can answer questions like number of books owned by maximum or minimum number of students.

## Overview

• Data and Statistics
• Categorical and Continuous Data
• Frequency & Tally Marks
• Bar Chart vs Histogram
• Drawing Bar Graph
• Choosing Right Scale for Bar Graph
• Vertical and Horizontal Bar Graphs
• Pictographs

HCF is 200

## The Art of Choosing the Right Scale

Not mandatory

In first case maximum values are even so we can choose the scale of 2.

Not mandatory

## Horizontal Bar Graph

HCF is 200

1. Maximum production year

2. Minimum production year

3. Largest decrease in production

4. Greatest increase in production

1. Maximum production year- 2002

2. Minimum production year- 2003

3. Largest decrease in production- 2003 (25)

4. Greatest increase in production 1999,2002 (10)

## Pictographs

• We start with subtraction - If I have apples and you take 3 from me, then I am left with 2 apples: 5 - 3 = 2.
• The value zero now becomes very important because I know that if I have 5 apples and you take away 5 apples then I am left with none, 0: that is 5 − 5 = 0