The questions can be stuck on the classroom walls at random. pupils can start at any question and when they find the answer to the chosen question then they can go to the question which the answer is written on the top left hand side of the sheet. If they are successful in answering all the questions correctly, they finish with the question which they have started with.
I reduced these and cut them into cards for the students to work on in pairs. After the first ones had finished I put the questions up on the interactive whiteboard and one student from each pair had to come up to the front to explain how they got the answer to one question. We thought the answer to how many teams can be made with more boys than girls should also include where there are no girls in the team.