The Cavern of Clues: Volume 4 by David Glover
The fearsome pirate Black Beard has buried his gold, and you have the map that leads the way. If you fail, you will be trapped inside the Cavern forever! It's a mathematical mystery of calculations, but will you survive until the end? Use your problem-solving skills and mathematical knowledge to decide how the pirate plot unfolds and to help save the day! Finding the answers will enable you to advance through this exciting adventure story, following the clues which are dotted along the way, and learning more about maths with every step you take.