Kjartan is freelance everything. Since getting his engineering degree, he has presented science programmes, worked seven years with Keith Chegwin on Swap Shop and Saturday Superstore, toured his one man show, played a lot of pub pianos very loudly and been Widow Twankey.

He has written many shows and pantomimes, twice winning the London Fringe Award for Best Production. He has had four shows published including his world-wide success Henry The Tudor Dude and his latest show Fawkes - The Quiet Guy. His other books include the Murderous Maths series (available in 15 languages), The Gobsmacking Galaxy from The Knowledge series, Dead Famous: Isaac Newton and his Apple, 3 cartoon books with cartoonist Stephen Appleby, 4 books in his notorious Killer Puzzles series and handbooks on Practical Jokes and Secret Codes. He has also written scripts for a wide range of children's TV and has written for Rosie & Jim comic, The Beano and The Oldie.

Kjartan works as a games consultant on shows including BBC's Get Your Own Back and Megamaths and he devised the millennium gameshow '2 for 2000'. His music for TV includes themes for all the BBC's Smart series, and frankly this petty list of dismal achievements goes on forever so that'll have to do. He's married to Bridget, has little girls Maisie, Florence, Dulcie, Miranda, a boxer dog Merlin and his mentionable hobbies include astronomy, church bell ringing and collecting copies of the Beano.

Kjartan has also written for The Alternative GCSE Guides series where he wrote the Maths guide and Warp Maze a full colour hardback with puzzles and mindbenders! He is famed for his Murderous Maths books, including his latest: Professor Fiendish's Book of Diabolical Brain-benders, Su Doku and Maths Kakuro and we have Kjartan's brilliant first work of Fiction Urgum the Axeman to look forward to in October 2006!