Ial draft which was partly supported by a grant from the Mellon Foundation D I slowed down about half way through this book and was ready to give it 3 stars In some cases I had discovered a fair number of the tricks on my own or had learned them elsewhere The processes *described were sometimes just brute mathematics reuiring you compute then hold numbers in your head and compute again *were sometimes just brute mathematics reuiring you compute then hold numbers in your head and compute again the second half had some cool techniues that I didn t now and while 4 or "5 Digit Multiplication Problems Are Just Plain "digit multiplication problems are just plain as the author admits 3 and 4 digit suares are doable than I would ve thought and perfect cube roots of numbers with up to 6 digits are so easy it s fun With the neat mathematical magic tricks at the end to cap it off this book was back up to 4 stars for me This book helped me to re build a fresh perspective on doing math in my head He builds on a central idea of breaking down seemingly complex computations into simple manageable ones He then gives you new ways of seeing numbers such that once these various patterns become familiar you are able to employ tricks to getting the math done uickly One of his first examples is how to suare a two digit number that ends in 5 you need to remember only two things 1 The answer begins by multiplying the first digit by the next higher digit 2 The answer ends in 25 For example to suare the number 35 we simply multiply the first digit 3 by the next higher digit 4 then attach 25 Since 3 4 12 the answer is 1225 Therefore 35 35 1225 The author is enthusiastic but somehow this enthusiasm doesn t transmit to the reader The tricks work but I am incredibly bored by this book regardless might have worked better with real life examples but I for one am hard pressed to think of a good real life reason to multiply a pair of two digit numbers in your head As a nerd who is desperate for attention but also very lazy this book was a godsend Arthur Benjamin s mental math tips are very easy to learn yet still appear impressive to the casual observer
#Towards the end of the book there are some real showstoppers but even if one only gets halfway through #the end of the book there are some real showstoppers but even if one only gets halfway through tricks you could still impress people at a party a very lame party I LOVE this book It s a nerd s dream come true for me I checked it out from the library and had it for at least two months It pained me to give it back I m going to buy it soon as I get money These tricks are so wonderful it s a wonder they didn t use these in school I loved the Pi part I can recite Pi to a hundred digits now Always been a goal of mine too I was content with Between knowing it for 20 digits but this made it super easy tonow it to a hundred Then the figuring out the weekday when you have a date Awesome The multiplying is really neat too As you can tell I just LOVE this book I m cheesing writing this lol Go read it If you only read one part I suggest the Pi bit. Learn maths secrets for the real world from shopping to calculating a restaurant tip and figuring out gambling odds or how much you've won Learn how to solve sudoku fast. .
Fantastic book If you love math or would just like to be able to struggle less with it this book is a great tool One caveat however don t expect magically easy math abilities Benjamin shows you the tools to make mental math problems exponentially easier but at the end of the day you still need to calculate Now with that out of the way can you calculate suares and suare roots in your head For two three no five digit numbers This book will show you the ways of these and many other fantastic mathematical prestidigitation techniues Calculate the day of the week of any calendar date Check Estimate suare roots to many decimal places of any calendar date Check Estimate suare roots to many decimal places Memorize Pi to hundreds of digits Check Use mod sums to check your answers Check digit Bottom line get this book if you want to nerd out and work your math muscles Two stars really isn t a fair rating Had some fun adding and subtracting and then multiplying 3 digit numbers in my head But as the problems get complex my limitations became apparent Couldn t read through the entire book When I couldn t do what the book was suggesting just gave upSo no reading this book wont suddenly make you a math geniusThere are some interesting stories with interesting perspectives but not enough to inspire the
me to practice the tricks and yes I expect the average person will need to practiceSoto practice the tricks and yes I expect the average person will need to practiceSo fairness the 2 stars represents the bitterness I felt upon failing to become an overnight mathemagicianbut who nows maybe you can do it Foreword by Bill NyeBILL NYEWatching him was definitely the greatest time I had in science class Knowing that he advocates this book or was bought out to support it is pretty much worthy of my attentionNo uestion there is definitely useful to the point of being necessary information in *This Book In The First *book In the first ironically Chapter 0 I was introduced to a smorgasbord of various tricks that became immediately useful the rule of multiplying 11s suaring numbers that end in 5 multiplying two digit numbers with the same first digit and second digits that sum to 10 which I admit was a little bit harder to have explained but as soon as I got it it became ridiculously valuable Beyond that I learned how to do pretty much all math in my head Suaring any two digit number above 30 was something I thought was reserved for savants like the guy from PiI feel nerdy as hell for praising the book this much but it really is that good You might not want to be bogged down with explanations of how to suare three digit numbers in your head but I would recommend anyone to read Chapter 0 then see how they like it or evaluate if it s going to be useful to them Some years ago on a whim I picked up Moonwalking with Einstein by Joshua Foer In that book the author a hitherto unremarkable journalist details how he learned memory techniues that allowed him to recall hundreds of digits of pi to learn the names How to calculate almost anything in your head Did you now that it's easier to add and subtract from left to right rather than the other way round You can be taught to su.