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Proportion
Last updated at January 15, 2026 by Teachoo
Class 8 (Ganita Prakash - 1, 2 & Old NCERT)
Chapter 7 Class 8 - Proportional Reasoning-1(Ganita Prakash)
- Observing Similarity in Change
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Basic Definitions
- Problem Solving with Proportional Reasoning
- Figure it out - Page 165-167
- Trairasika—The Rule of Three
- Figure it out - Page 170-171
- Acitvity and Question - Page 171
- Sharing, but Not Equally!
- Figure it out - Page 175
- Unit Conversion
- Figure it out - Page 176, 177
Transcript
ProportionIf two ratios are equal, we say they are in proportion Example: To check how they are equal, We simplify the ratios 2 : 4 = 2/4 4 : 8 = 4/8 So, we write 2 : 4 ∷ 4 : 8 And we say that, 2, 4, 4, 8 are in proportion When we write 4 numbers in proportion - 2, 4, 4, 8 It means 2 : 4 ∷ 4 : 8 And, 2, 8 are called extreme terms 4, 4 are called middle terms Let’s do a question Are 10, 20, 40, 80 in proportion? Ratio of 10 & 20 = 10/20 = 1/2 = 1 : 2 Ratio of 40 & 80 = 40/80 = 4/8 = 1/2 = 1 : 2 ∴ 10 : 20 = 40 : 80 So, 10, 20, 40, 80 are in proportion
