Test your reflexes as well as your arithmetic in this challenging game for the BBC B by Nicholas Green of Hampstead, London. First you must shoot your sum as it whizzes past on the rifle range - press RETURN to fire.

After a direct hit, three possible answers are displayed, and you have two seconds in which to key either 1, 2 or 3 for whicever answer you think is correct.

Your score is displayed at the end of Mathsground and you have three speeds, from fast to supersonic, from which to choose.