# Fast Calculation Questions — Free Timed Practice | ComputePrep > Practise fast calculation questions free and timed: round and adjust, split the multiplier, and work left to right. Worked solutions on every timed drill. Source: https://computeprep.com/drill-types/fast-calculation --- Speed arithmetic # Fast calculation questions — the mental arithmetic the clock actually tests Fast calculation questions are plain arithmetic against a clock, and speed comes from three habits rather than talent: round to a convenient number and adjust afterwards, split an awkward multiplier into easy pieces, and work left to right so the leading digits settle first. None requires a memorised trick. Every quant question contains arithmetic, so calculation speed is the multiplier on the whole section rather than a topic within it. It is also the most trainable thing in the paper — the gap between a slow and a fast candidate is habit and repetition, not aptitude, and it closes within weeks of timed practice. **Try it against the clock.** Speed Arithmetic runs at 15s easy, 20s medium and 30s hard. The clock is stamped and judged on our server, so the limit you see is the deadline that is actually enforced — and it starts when you tap Start, not while the question is loading. [Start a timed Speed Arithmetic drill →](https://computeprep.com/?drill=speed_arithmetic&src=seo-fast-calculation) ## How fast calculation questions are actually done quickly - Round, then adjust For 97 × 6, compute 100 × 6 = 600 and subtract 3 × 6 = 18, giving 582. Rounding to a convenient number and correcting is almost always faster than working with the awkward number directly, and the correction is usually a single-digit multiplication. - Split the multiplier into easy parts To multiply by 15, take ten times the number plus half of that. To multiply by 25, divide by 4 and multiply by 100. Choosing the split is the skill; each piece is then trivial. - Work left to right, not right to left Adding 456 and 378 as 700, then 120, then 14 gives 834 and settles the leading digits first — so if the options differ in the hundreds you can stop early. School arithmetic runs right to left because of paper carrying; mental arithmetic should not. - Let the options set the precision When options are widely spaced, an estimate is the answer and exact arithmetic is wasted. Read the options before computing — this saves more time across a paper than any individual shortcut. ## Splits worth knowing by reflex | To multiply by | Do this | | --- | --- | | 5 | Halve, then × 10 | | 15 | × 10, plus half of that | | 25 | ÷ 4, then × 100 | | 9 | × 10, minus the number | | 11 | Outer digits, sum in the middle | | Near 100 (97, 98) | × 100, minus the deficit × the number | ## 3 real fast calculation questions, with worked solutions Generated by the same engine that mints the ComputePrep daily. Each answer is computed from the numbers printed in the question, and the walkthrough below each one is the engine's own working — not a solution written afterwards. Reload this page's live drill and you get different numbers. ### Question 1 809 − 152 = ? Solve in your head — beat the clock. - 647 - 757 - 657 - 658 - 667 - Compute directly: 809 − 152 = 657. ### Question 2 72 × 7 = ? Solve in your head — beat the clock. - 432 - 497 - 504 - 576 - 511 - Compute directly: 72 × 7 = 504. ### Question 3 190 ÷ 5 = ? Solve in your head — beat the clock. - 36 - 37 - 39 - 28 - 38 - Think multiplication: 5 × ? = 190. Since 5 × 38 = 190, the answer is 38. ## Common mistakes this drill is built from The wrong options are not random numbers. Each one is the result of a specific careless error for this topic, so picking one tells you which habit is costing you marks. ### Computing exactly when an estimate would do The most expensive habit in the section. Glance at the option spread first and let it decide how much precision the question actually needs. ### Working right to left out of habit Right-to-left exists because of paper carrying. Mentally it hides the leading digits until last, which is exactly the information that would let you stop early. ### Practising without a clock Untimed practice trains accuracy you already have. Speed only improves under the pressure it is meant to withstand, which is why every drill on this page runs on a server-enforced timer. ## FAQ ### How do I get faster at mental calculation for bank exams? Build three habits — round and adjust, split awkward multipliers, and work left to right — then drill them against a clock daily. Speed here is repetition rather than talent, and most candidates see a clear difference within two to three weeks of consistent timed practice. ### Do I need vedic maths to calculate fast? No. The general habits on this page cover most exam arithmetic and apply to any numbers. Vedic techniques are faster still but each applies only to a specific shape of number, so they are worth adding once the general habits are automatic — not instead of them. ### What should I memorise to speed up calculation? Squares to 30, cubes to 15, the fraction equivalents of common percentages, and tables to 20. That recall base removes a large share of the arithmetic in a quant section outright, which is faster than computing quickly. ## Practise the next topic - [All 23 drill types](https://computeprep.com/drill-types) — the full rotation with every published time limit. - [Simplification questions — BODMAS](https://computeprep.com/drill-types/simplification) — simplification questions, timed. - [Percentage questions for bank exam papers](https://computeprep.com/drill-types/percentages) — percentage questions for bank exam, timed. - [Vedic maths shortcuts](https://computeprep.com/vedic-maths) — the seven sutras that make a 15-second answer possible. - [How to improve calculation speed](https://computeprep.com/calculation-speed) — the six-week arc these drills fit into. ComputePrep is free, needs no account, and is not affiliated with IBPS, SBI, SSC, RRB or any exam authority.