Joel and Samuel Ucko publish a book, aged nine and seven (and they'll even give an assembly on it)

Brothers Joel and Samuel Ucko have published their first puzzle book. Aged nine and seven respectively, the pair (Joel pictured right) developed the book after a suggestion from their father, Gavin.

Mr Ucko is the managing director of the Happy Puzzle Company and author of several puzzle books, including All Clued Up!, targeted at youngsters aged nine and upwards. He thought it would be a good idea to create a version for younger children, so he put his children on the case. The result? All Clued Up! Junior. Aimed at children aged five to eight, the book has generated a lot of interest from primary schools, with more than 1,500 orders in a few weeks.

The boys are both students at Hasmonean Primary School in Barnet, and attend Edgware Adath Yisroel Synagogue.

Samuel tells People: "We have been allowed to give a copy of the book to everyone in our classes at school and our head teacher, Mrs Rodin, also called us up to talk about the book in assembly."