Approximation Questions with Solutions

Approximation questions aren’t asking for the exact answer — they’re asking for the answer closest to the options given, so rounding every number first is the technique, not a shortcut around it. Here’s the concept, four fully worked examples, and a few to try yourself.

The concept, quickly

• Round every number in the expression to a convenient nearby value FIRST — nearest whole number for decimals, nearest multiple of 10/100 for percentages and large numbers, nearest perfect square under a square root.
• Then calculate normally using BODMAS with the rounded numbers — the goal is a value close to the exact answer, not the exact answer itself.
• Round consistently: if you round one number up, the overall error is usually small as long as you don’t round several numbers in the same direction by a large margin.
• This is a pure speed technique for multiple-choice questions where the options are spread far enough apart that an approximate value clearly identifies the right one.

Worked examples

Try these yourself

Round each number first, then calculate, and check against the answer.

Where this comes up

Approximation is tested directly in the Quantitative/Numerical Aptitude section of every exam Pariksha Saathi covers — SSC CGL, SSC MTS, SSC CHSL, IBPS PO, IBPS Clerk, SBI PO and SBI Clerk — usually as a dedicated set of 5 quick-calculation questions.

Practice more Approximation questions

This page covers the concept and a handful of worked examples. Pariksha Saathi has full topic-wise practice sets for Approximation (and every other Quant/Reasoning/English topic) with instant scoring and explanations — free, no account required.