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Simplification — BODMAS, Fractions, and Fast Calculation | TNPSC, SSC, Bank

Learn simplification shortcuts using BODMAS, fractions, decimals, surds, and approximation with worked aptitude examples.

~2 min read

Quick Concept Summary

Simplification questions test accuracy under time pressure. Most mistakes come from ignoring the order of operations or converting fractions too late.

Core Rules

RuleExample
Brackets first(18 + 6) / 3 = 8
Division and multiplication left to right24 / 6 x 2 = 8
Convert percentages early25% of 240 = 1/4 x 240 = 60

Worked Examples

Example 1

36 / 6 x 4 + 8 = 6 x 4 + 8 = 32

Example 2

3/5 of 250 + 20% of 150 = 150 + 30 = 180

Example 3

sqrt(144) + 18 / 3 = 12 + 6 = 18

Shortcuts

  • Memorise common squares up to 30.
  • Replace 12.5%, 25%, 50%, and 75% with 1/8, 1/4, 1/2, and 3/4.
  • Keep decimal conversion for the final step when fractions are cleaner.

Practice Questions

1. Simplify 48 / 8 x 5 - 6. 2. Find 35% of 400 + 3/4 of 80. 3. Simplify sqrt(225) + 64 / 8. 4. Evaluate (18 + 12) / 5 x 4.

Common Mistakes

  • Doing addition before multiplication
  • Reading of as a separate operation instead of multiplication
  • Rounding too early

Frequently Asked Questions

Resolve brackets first, then powers or roots, then division and multiplication from left to right, then addition and subtraction.