Class 9 · Chapter 11
The World of Algorithms
An algorithm is a step-by-step recipe. Explore ancient and modern algorithms for arithmetic and number theory.
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Ganita Manjari · Class 9 (2026-27)
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Detailed theory
A cake recipe is close to an algorithm — but only if every step is unambiguous. "Bake till golden" is subjective. In mathematics we insist every step has one, and only one, interpretation.
Key concepts & formulas
01
An **algorithm** = a finite sequence of unambiguous steps that solves a well-defined problem.
02
Long division is an algorithm you already know — every step is deterministic.
03
**Euclidean algorithm** for HCF: until remainder is .
04
A flowchart visualises decision points and loops.
05
Two algorithms can solve the same problem with very different amounts of work — this is why efficiency matters.