Quick Revision Notes & Formula Sheet

Class: 6th Mathematics
Chapter: Data Handling
Board: MP Board (NCERT Curriculum)

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### Concept 1: What is Data? (डेटा क्या है?)

• Definition: Data is a collection of numbers or information gathered to answer a specific question or represent facts.
• Example: Marks obtained by students in a Mathematics test, temperatures of different cities in a week.
• Raw Data (कच्चा डेटा): The data collected in its original, unorganised form is called raw data.

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### Concept 2: Recording and Organising Data (डेटा को व्यवस्थित करना)

To make sense of data, it needs to be organised.

• Frequency (बारंबारता): The number of times a particular observation or value occurs in the data.
• Tally Marks (टैली मार्क्स): A quick way to count and record data using vertical and diagonal lines.
  • 1 is written as |
  • 2 is written as ||
  • 3 is written as |||
  • 4 is written as ||||
  • 5 is written as [Cancel with diagonal: ||||] (Every fifth mark is drawn diagonally across the first four).

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### Concept 3: Pictograph (पिक्टोग्राफ)

• Definition: A pictograph represents data through pictures or symbols of objects.
• Key Point: Always check the Key/Legend of the pictograph, which tells you how many units a single picture represents (e.g., 🍎 = 10 apples).

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### Concept 4: Bar Graph (बार ग्राफ)

• Definition: A display of information using bars of uniform width, drawn with equal spacing between them on a horizontal or vertical axis. The heights or lengths of the bars represent the values (frequencies).
• Key Features:
  1. Axes: Two perpendicular lines—Horizontal axis ($X$-axis) and Vertical axis ($Y$-axis).
  2. Scale: The ratio chosen to represent a larger number with a smaller length (e.g., $1\text{ unit length} = 5\text{ students}$).
  3. Equal Spacing: The gap between consecutive bars must be uniform.

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### Important Tips for MP Board Exams

1. Always write the Scale: When drawing a bar graph or pictograph, clearly mention the scale chosen at the top right corner.
2. Label the Axes: Do not forget to label the $X$-axis and $Y$-axis (e.g., $X$-axis: Names of students, $Y$-axis: Marks obtained).
3. Neatness: Use a sharp pencil and a scale (ruler) for drawing bar graphs and tally tables.