Johnny has written a number of books over the years.
His new book, Wonders Beyond Numbers - A Maths History is due to be published by Bloomsbury Press in May 2017.
Other books that are still available to buy on Amazon include:
Think of a Number (DK 2005) Sells worldwide, USA, China, Korea, Azerbaijan etc.
Go Figure (DK 2005) American version of the above. Third impression 2016.
Ball of Confusion (Icon Books 2011) - Maths Puzzles for all ages.
Mathmagicians (DK 2008) - on Measurement. Sells worldwide.
Second Thinks (Puffin 1987)
Plays for Laughs (Puffin 1983)
Think Box (Puffin 1982)
Think of a Number (BBC 1979)