From the Introduction
By now if you have worked through the previous four books your mathematical skill are developing well and your intelligence and intellect are suitably exercised. In Book 5 we have more challenging mathematical techniques for you to master together with a whole new set of Fact Files. You are also encouraged to continue your development of mindmaps for each Fact File. Mindmapping is a powerful technique for aiding the general learning process. Remember your mindmaps are a visual means of representing information - based on the belief that visual knowledge is easier to absorb than linear text.
Contents of Book 5