This book is simply fantastic. When buying it, I was worried that like most maths books, it would be really dry and impossible to understand. However I am so glad I invested in it, because by completing every question (save the ones with blue boxes, which were intended for further maths) I was able to gain the proficiency and confidence to glide through core 3 and 4, which really require a massive amount of practice. The explanations are really thorough, all you need is the patience and persistance to complete the book from start to finish. In all, the best academic book I have ever bought.