Kjartan Poskitt is an author and BBC children's award show host. His children's books have been translated into about 30 languages and include the Murderous Maths series of books as well as books on space, puzzles, codes, magic, five historical musicals and several funny novels including the Agatha Parrot series. As well as touring with his math and space shows, he's been a TV presenter, piano player, and has composed several TV theme songs. He was born and lives in York, England with his wife and four daughters. Ian Baker is a professional cartoonist working in the fields of press, greeting cards, illustration, advertising and television. His illustrations have appeared in publications for Private Eye, Reader's Digest, National Lampoon, Nickelodeon, The Spectator, Prospect, Emotional Rescue, Paperlink, Gibson Hanson, BBC, Saga Magazine, and more.