Quick Compare · Number Sense Test
Two amounts appear — sometimes plain numbers, sometimes quick sums like 17 + 24 or 6 × 9. Tap the bigger one. 45 seconds on the clock.
How to play Quick Compare
Each trial shows two panels. Tap the one with the larger value (arrow keys work too). Plain numbers just need a glance; sums and products need a beat of mental arithmetic. +1 for correct, −1 for wrong.
What it measures
Quick Compare taps your approximate number system — the built-in sense of magnitude that lets you judge 'bigger' without computing exactly — plus arithmetic fluency when expressions appear. Sharper magnitude judgement is closely linked to comfortable everyday maths.
Honest note: You don't always need the exact answer — estimating '6 × 9 is about 54, that beats 49' is the actual skill. Compute only when the gap is tight.
What's a good score?
Around 20 is typical; 30+ means your number sense is doing the work before your calculator brain even wakes up. The percentile we show is an estimate based on typical distributions, not a clinical norm.
FAQ
Should I calculate or estimate?
Estimate first. If the two sides are obviously far apart, magnitude sense alone is enough; save real arithmetic for close calls. Knowing when to switch is part of the skill.
Why do close pairs feel so much harder?
That's the ratio effect — a signature of the approximate number system. Discriminating 52 vs 54 is genuinely harder for the brain than 20 vs 60, in a smooth, measurable way.