Sixty seconds. Answer as many as you can. Every answer is a whole number.
Each question is worth what it usually takes to do, times ten. A hard one you get is worth several easy ones.
A wrong answer or a skip costs half the question, so a guess is not free and neither is passing. Get about a third of them right and you break even.
Press enter to answer. Typing the right digits does not send them, so a long answer is safe. Signed out, everything works and nothing is kept.