Open University are giving away FREE BBC puzzle books for you to test your code-breaking abilities! Claiming yours is simple - just fill in the short form and your book will be sent out in the post.
Click 'GET FREEBIE' and scroll down to 'order your free mathematical puzzles'. You'll then be taken to a short form which you'll need to fill out with your name and address.
The book accompanies the BBC show 'The Code' so if you're a big fan of the programme then you'll adore this freebie!