60 seconds on the clock. Answer as many as you can — wrong answers don't cost you time, just keep going.
A 60-second countdown starts the moment you click Start. Answer each addition/subtraction/multiplication question and hit Enter — a correct answer instantly loads the next question, a wrong one just moves on (no penalty besides not scoring). When time runs out, your total correct count is shown and saved if it's a new best.
No — a wrong answer simply doesn't add a point and moves you straight to the next question, so speed matters more than caution.