Penny Worms is an author of many educational books for kids, including several maths activity books. She lives in Tunbridge Wells, England. Kasia Dudziuk is a member of the Association of Illustrators and House of Illustration. She has worked on a prestigious list of internationally acclaimed children's brands, such as Barbie, Thomas the Tank Engine, Mr Men and Little Miss and Winnie-the-Pooh. Her clients include Egmont, Usborne, Marks & Spencer and Sainsbury's. She lives in London, England.