10 questions. Gets harder as you go. How fast can you finish?
Ten questions, mixed addition, subtraction, multiplication and division. Difficulty increases as you progress — early questions use small numbers, later ones use bigger ones. Your best time is saved on this device so you can try to beat it.
No — take as long as you need per question, but your total completion time is tracked and saved as your best score.
Your best time is saved in your browser (locally on your device), so it will still be there next time you visit — unless you clear your browser data.