First of all this book has really changed the way I see math and its everyday applications.<br><br>Now then as for the book its self, its definitely a fantastic book to say the least.<br><br>I think the composition of it is fair and its certainly an easy read, even though its a math book it contains some interesting (by interesting I mean not boring as you would expect a book on math to be) facts and amusing insights.<br><br>As for the methods I can personally vouch for their validity and their simplicity.<br><br>All the methods when following the rules obviously are easy to remember and with a little practice you will certainly surprise yourself with your new found abilities.<br><br>I cannot recommend this book enough, mental math skills is something we seem to be lacking more and more in modern society because our dependence on technology.  I say ease off tech. a little bit and rely on your mind more its more powerful than a lot of people realize.