80 in 8 arithmetic practice
By default: 80 questions, eight minutes.
Preparing your game…
How to play
Enter submits; incorrect answers advance. Skip moves on. The clock continues, even in another tab.
Full round rules
- Choose Start round. A three-second countdown gives you time to get ready. The clock starts after the countdown.
- Type your answer and press Enter or choose Submit. An incorrect submission advances too; the previous-answer cue shows the expected answer. Review the question after the round.
- Use Skip to move on without submitting. Skips earn no points and remain separate in your review.
- The round ends at the question target or when time expires. You can also choose Finish round to end early.
Open Settings while idle to change the target, duration or question families. Game changes apply to your next round.
Practice and improve
Try a method slowly before using it against the clock. Review your 80 in 8 stats to choose what to practice next.
Fraction example (untimed)
This separate example has no timer and saves nothing.
Show method and answer
- 1/4 + 1/4 = 2/4: the denominator stays 4.
- Divide numerator and denominator by 2: 2/4 = 1/2.
1/4 + 1/4 = 1/2
Reference and local history
Score, accuracy and comparisons
Your score counts correct answers. Submitted-answer accuracy is correct submissions divided by all submitted answers. Skips and unanswered questions are separate; with no submissions, accuracy is unavailable.
Compare completed rounds with matching settings. Timed correct solves and their sample count can help you choose practice; an early finish or a drill is a different task.
Backup and storage details
JavaScript is needed to play; IndexedDB is needed to save history. If saving fails, the result stays available with retry and explicit discard controls. Download or restore a JSON backup in Stats: Your data. The backup includes both games and settings. History does not automatically sync between devices; clearing browser storage can remove it. No account is required and there are no ads. Optional PostHog analytics collect usage summaries; your saved questions, answers and backup contents stay local.
Exact question mix and generation settings
The default pool gives integer addition, subtraction, multiplication and division a probability of one sixth each. Decimal addition/subtraction and fraction addition/subtraction have one twelfth each. Settings let you disable families, select multiplication subtypes, allow negative first operands, cap fraction denominators, and change the question target or time. Changing enabled families changes the mix.