Quantitative Aptitude – “Tables”
(Lakshadweep Police Sub‑Inspector, SI – Quantitative Aptitude)
Tables in quantitative aptitude usually refer to the multiplication and division tables (often called “multiplication tables” or “tables of 5, 10, 12, etc.”).
They help you solve problems quickly, check facts, and remember patterns.
1. Simple Explanation
| Concept | What it Looks Like | Why It Helps |
|---|---|---|
| Multiplication Table | 1 × 1, 1 × 2, …, 12 × 12 | Gives instant products; shows patterns (last digits, powers) |
| Division Table | 12 ÷ 1, 12 ÷ 2, …, 12 ÷ 12 | Allows you to find quotients without long division |
| Factor Table | List of factors of a number | Quickly spot multiples, divisibility, and prime factors |
| Power Table | 2¹, 2², …, 2⁹ (or 10⁰–10⁵) | Handy for exponential problems, percentages, ratios |
Key Idea – Memorize the “core” tables (5, 10, 12, 15, 25, 50, 100).
The rest can be obtained by simple adjustments.
2. Key Points / Rules
| Rule | How to Use | Example |
|---|---|---|
| Last‑digit cycle | Products of numbers ending in the same digit repeat every 10. | 7 × 3 = 21 → last digit 1; 7 × 13 = 91 → last digit 1 again |
| Multiples of 9 | Sum of digits of a product is 9, 18, 27… | 9 × 13 = 117 → 1+1+7 = 9 |
| Square & Cube Patterns | 1²=1, 2²=4, …, 9²=81; 2³=8, 3³=27… | 6²=36 → 6 × 6 |
| Using 5’s Table | 5×n = (n/2)×10. |
5 × 14 = 7 × 10 = 70 |
| Using 10’s Table | 10 × n = n followed by 0. | 10 × 23 = 230 |
| Using 12’s Table | 12 × n = (10 × n) + (2 × n). | 12 × 7 = 70 + 14 = 84 |
| Division by 2, 5, 10 | Drop the last digit for /2, add a zero for /10, remove last digit for /5. | 32 ÷ 2 |