Speed Estimation Techniques

Practice bank for UCAT Quantitative Reasoning questions where exact calculation is unnecessary — the answer options are far enough apart that estimation is faster and safer.

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Quick-Reference: Estimation Strategies

When to Estimate

Estimate when the answer options are spread far apart (e.g. 12, 25, 48, 96). If options are close together (e.g. 47, 49, 51, 53), you need an exact calculation.

Estimation Techniques

Technique	How it works
Rounding	Round numbers to 1 significant figure before calculating
Benchmarking	Use known benchmarks: 10%, 25%, 50%, 33%, 1/3
Bounding	Calculate a lower and upper bound to trap the answer
Order of magnitude	Determine if the answer is in the tens, hundreds, or thousands
Elimination	Rule out options that are clearly too large or too small

Rounding Rules for Speed

• 387 becomes 400 (round to nearest hundred)
• 4,720 becomes 5,000 (round to nearest thousand)
• 0.48 becomes 0.5 (round to nearest 0.5)
• 17% becomes 1/6 or 20% (use the nearest easy fraction)

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Strategy