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Question 3 - Figure it out - Page 69 - Chapter 3 Class 8 - A Story of Numbers (Ganita Prakash)
Last updated at November 24, 2025 by Teachoo
Figure it out - Page 69
Class 8 (Ganita Prakash & Old NCERT)
Chapter 3 Class 8 - A Story of Numbers (Ganita Prakash)
- Introduction
- The Mechanism of Counting
- Some Early Number Systems
- Roman Numerals
- Figure it out - Page 60, 61
- Egyptian Number System
- Variations on the Egyptian System and the Notion of Base
- Adding Egyptian Numerals
- Multiplying Egyptian Numerals
- Distributive Law – For Egyptian Numerals
- Abacus that Makes Use of the Decimal System
- Shortcomings of the Egyptian System
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Figure it out - Page 69
- Mesopotamian Number System
- Mayan Number System
- Chinese Number System
- Hindu Number System
- Evolution of Ideas in Number Representation
- Figure it out - Page 80
Transcript
Question 3 Give a simple rule to multiply a given number by 5 in the base-5 system that we created.Rule: The rule is to "Shift Up" every symbol to the next landmark. Explanation In a Base-5 system, the landmark numbers are powers of 5 (1, 5, 25, 125...). If you take any landmark number and multiply it by 5, it becomes the next landmark number 1 × 5 = 5 5 × 5 = 25 25 × 5 = 125 Therefore, to multiply a complex number by 5, you simply replace each symbol with the symbol of the next higher value. Example: If your number is \square \triangle \triangle (One 5 and two 1s = 7). Multiply by 5: The Square becomes a Hexagon (25), and the Triangles become Squares (5s). Result: \hexagon \square \square (One 25 and two 5s = 35). Check: 7 × 5 = 35. The rule works!
