Number Analogy
Analogies: Number Analogy
Number Analogy
Number Analogy
What you'll learn
- Find the rule linking the first pair of numbers.
- Apply the same rule to the second pair.
- Common rules: double, half, add a fixed number, multiply by itself.
Key concepts
Level 1 — Core idea
Verbal: "2 is to 4 as 3 is to 6" — the rule is "double the first number".
Symbolic: A : B :: C : D, where B = f(A) and D = f(C), using the same function f.
Visual: Picture a machine: put a number in, a rule works on it, and a new number comes out. The same machine works on both pairs.
Level 2 — Going deeper
Some rules add a fixed amount instead of multiplying. Always check the pair with subtraction first (B − A) and division (B ÷ A) to discover whether the rule is "add" or "multiply".
NCERT anchor
NCERT Math Mela, Class 3 — Multiplication and patterns — doubling, halving, and skip-counting rules connect directly to this reasoning skill.
Worked example
3 : 6 :: 5 : ?
Step 1 — 6 ÷ 3 = 2, so the rule is "double the first number".
Step 2 — 5 × 2 = 10.
Answer: 10
4 : 7 :: 8 : ?
Step 1 — 7 − 4 = 3, so the rule is "add 3".
Step 2 — 8 + 3 = 11.
Answer: 11
Common mistakes
| Mistake | Why | Fix |
|---|---|---|
| Assuming it's always "double" | Common rule seen too often | Check subtraction AND division before deciding |
| Using a different rule for the second pair | Rule not applied consistently | Use the same rule both times |
| Arithmetic slip | Rushed calculation | Recheck the sum or product once more |
| Ignoring the direction | Confusing A→B with B→A | Always work from the first number to the second |
Quick check
- 5 : 10 :: 6 : ?
- 10 : 5 :: 20 : ?
- 2 : 5 :: 4 : ?
- Stretch: 3 : 9 :: 4 : ? (square rule)
Revision tip: Try division first — if it gives a whole number, that is likely the rule.
Open the Practice tab for graded questions on Number Analogy.
Key Takeaways (TL;DR)
- What you'll learn
- Key concepts
- Worked example
- Common mistakes
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