Class 8 · Chapter 7
Proportional Reasoning-1
Ratio, proportion, unitary method, and direct variation.
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Ganita Prakash · Class 8 Part 1 (2026-27)
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Detailed theory
Reduce to simplest form: . Same units on both sides. Compare via cross-multiplication.
Key concepts & formulas
01
**Ratio** compares two like quantities.
02
**Proportion**: two ratios equal — iff .
03
**Unitary method**: find value of one unit, then scale.
04
**Direct variation**: , i.e., .
05
Percentage = ratio with denominator 100.