60-second understanding game · #2
Percentage Instinct
One purchase, two discounts, no math allowed: what do you actually pay? Lock your gut answer — then meet the receipt. The gap between the two is the most useful thing this page teaches.
A $80 item is 25% off — and at checkout a coupon takes another 15% off.
What do you actually pay? Gut answer — no math allowed.
Why a game instead of another percentage paragraph
Everyone "knows" percentages — until two discounts stack. Most guesses land on the added-total (25% + 15% = 40% off) because addition is what brains reach for; registers multiply instead, and the second discount only bites what's left. Feeling that gap once at a fake checkout is cheaper than feeling it at a real one — and it's the same instinct that misreads "50% off, then 50% off" as free.
Fair play, by our rules: the game runs entirely in your browser, guesses aren't recorded anywhere, and the math is the same audited formula as our percentage calculator — see how we verify.
Why the register wins
Stacked discounts multiply, they never add: 25% off then 15% off is ×0.75 × 0.85 = ×0.6375 — a 36.25% cut, not 40%. The second discount only bites what's left after the first, and that gap is exactly where shopper intuition loses money. The same multiplication explains why a 50% loss needs a 100% gain to break even.
When the game has recalibrated your gut, run any real price through the Percentage Calculator — including reverse percentages and stacked changes.