I completely agree with the last reviewer. This is a complete pearl of a maths book. I have read - as a maths teacher - a lot of very poorly written, poorly explained books in my time, and so it was a complete relief to find a book which explained everything so easily.
I have taken the tricks in this book and taught them to my Primary 3 class - they were really pleased to know how to multiply any number by 11, and the ways of completing the maths calculations are just like they are now being taught in the their maths lessons.
I am confident that this would be a perfect gift for anyone - it is a great gift to any teachers or anyone revising for any of their maths exams. What is great about the book is the paper and pen section, which shows some super simple ways to check any addition is correct.