The sprint flips the board format on its head: 20 mixed problems, but only one on screen at a time, and you must clear the current one to see the next. You get one minute. The score is how many of the 20 you solve before the clock reaches zero.
The ranges are the same friendly ones as the practice boards — times-table facts like "9 × 6" and two-digit sums like "48 + 27" — so the challenge is pure tempo, not difficulty. Clearing all 20 inside the minute is hard; most players do not manage it on a first run.
How to play
You have one minute. The clock starts at your first keystroke, not when the page opens.
Problems come one at a time, in order — no skipping ahead.
Type the answer; an exact match commits instantly and the next problem appears. Enter is optional.
A wrong answer on Enter shakes the box and clears it — no penalty, just lost seconds.
The run ends when the minute is up, or sooner if you solve all 20.
Your score is the number you solved. A tie is broken by the faster time.
Give up ends the run early and shows your results.
What counts in this quiz
20 problems per sprint, each randomly one of +, −, × or ÷ at easy ranges.
Additions use numbers 12–89, subtractions stay under 100 with positive answers, multiplication is tables to 12 × 12, division is always exact with divisors 2–9.
Unlike the boards, answers can repeat between problems — you only ever face one at a time, so it doesn't matter.
Good to know
In 1980 Shakuntala Devi multiplied two randomly chosen 13-digit numbers in her head in 28 seconds — a Guinness World Record.
Fast mental adders usually work left to right — hundreds first, then tens, then ones — the reverse of how it's taught on paper.