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How Many Socks Make a Pair?: Surprisingly Interesting Maths by Rob Eastaway

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Do you gaze into your washing basket and wonder how long it'll take to find a pair of socks? Behind this question is a world of maths that can be creative, surprising and sometimes even beautiful. Using playing cards, a newspaper, the back of an envelope, a Sudoku, some pennies and of course a pair of socks, Rob Eastaway shows how maths can demonstrate its secret beauties in even the most mundane of everyday objects. Among the many fascinating curiosities in these pages, you will discover the strange link between limericks and rabbits, an apparently 'fair' coin game where the odds are massively in your favour, why tourist boards can't agree on where the centre of Britain is, and how simple paper folding can lead to a Jurassic Park monster. With plenty of ideas you'll want to test out for yourself, this engaging and refreshing look at mathematics is for everyone.

Paperback

First published August 14, 2008

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383 people want to read

About the author

Rob Eastaway

47 books31 followers
Robert Eastaway is an author who is active in the popularisation of mathematics. He is a former pupil of The King's School, Chester, England and has a degree in Engineering and Management Science from the University of Cambridge. He was President of the UK Mathematical Association for 2007/2008. Eastaway is a keen cricket player and was one of the originators of the International Rankings of Cricketers. He is also a former puzzle-writer for the New Scientist magazine and he has been involved in live mathematics shows on Virgin Radio (now Absolute Radio). He is the Director of Maths Inspiration, a national programme of maths lectures for teenagers which involves some of the UK’s leading maths speakers such as Simon Singh and Colin Wright.

Robert Eastaway's titles appear under the name "Rob Eastaway" in the UK and some other countries.

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5 stars
64 (23%)
4 stars
106 (39%)
3 stars
81 (29%)
2 stars
17 (6%)
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3 (1%)
Displaying 1 - 21 of 21 reviews
Profile Image for Baby Adam.
50 reviews
June 30, 2019
Some really nice material in there, and very well presented. I'd like to give it five stars, but I found a few things somewhat #triggering in a highly enjoyable and inspiring miscellany:

(i) Eastaway presents the fact that x^0 =1 as a mathematical convention, and hence misses the point that it makes sense. The number system would not run anywhere near as smoothly with any other choice for the value of x^0.

(ii) A rounding error, come on!

(iii) When talking about infinity, the "1-1+1-1+1-1+1-..." series is discussed, and the fallacious argument showing that the value of the sum is 1/2 is presented. However, Eastaway makes the #outrageous claim that "there are mathematicians who believe 1/2 is the best answer" #lolnope

I'd definitely recommend this book, so do not be put off, although I very much enjoyed ranting about some rather minor points.
Profile Image for Maddy.
17 reviews
February 7, 2021
This book had some interesting points but also felt patronising at times.

It was also frustrating that the way many chapters went seemed to be “hey look at this really cool thing that happens, and the reason that this happens is because of maths”. Well ok... WHAT maths? It stopped just before it got interesting.

I think I went into this book with the wrong understanding of who it was aimed at. It might be well suited to spark an interest in maths for someone who doesn’t think they like it or perhaps for some children, but if you’re actually already interested in the subject it’s probably not for you.
8 reviews
March 29, 2021
Interesting topics but doesn't go very deep. I was left wanting more.
7 reviews
December 30, 2020
I enjoyed this book. It has a lot of neat observations, and it's separated into chapters, where if you're not interested in a particular chapter, you can skip over it.

To give you an example, I'll show one of the puzzles from the book:

"Two trains are approaching each other on the same track, each traveling at 50 mph. When the trains are 100 miles apart, a fly that always flies at 60mph, sets off from the front of Train A directly toward the oncoming Train B. When it gets to Train B it turns around and heads straight back towards A, and it continues to fly back and forth between the two trains until CRUSH! the two trains smash into each other, crushing the fly in the process.

How far did the fly fly - before it met its unfortunate end?"

There are two ways of solving the problem - one involving taking the limit of a geometric series, and the other is a simple and elegant solution. If you enjoy brain teasers like this, you'll enjoy this book.
Profile Image for Jeff Duda.
50 reviews
January 22, 2023
Great short read on the true spirit of mathematics - a mix of practical and theoretical. So many good examples to teach people math at many levels of intensity and rigor!

The references are mostly suited towards a UK audience, so this American reader was somewhat unfamiliar with some of the examples.
Profile Image for Pashmina.
266 reviews22 followers
July 12, 2019
Very interesting, but in my case, not so surprisingly. (I love maths!)
Profile Image for Lucy Pallent.
12 reviews
January 6, 2021
Too basic to recommend to anyone above the age of 14. A fantastic intro book for younger readers with an interest in numbers.
Profile Image for Andy Venn.
51 reviews1 follower
February 2, 2025
This is a pretty good popular maths book. Well written, lots of tips and shortcuts. One of those books you can easily dip in and out of.
65 reviews1 follower
March 12, 2024
Great book filled with interesting math problems, but not for those who actually like math - solutions are not explained so everything you learn is quite shallow. You may impress your friends with some neat math facts, but you won't be able to answer "why?". I expected a little more, but that's not what this book is. But for what it is, it's a very well-written and entertaining book, easy and pleasant to read, I would recommend.
Profile Image for Nurture Waratah.
137 reviews3 followers
January 25, 2013
This book is full of interesting maths facts, card tricks, word problems and other fun facts and puzzles. Every chapter had something new for me to learn, not all of which would be traditionally viewed as mathematics by the average layperson. I found this book both fascinating and incredibly informative and I recommend it to anyone with the slightest interest.

I should warn you, though, some of the chapters will definitely make your brain hurt - especially the chapter about infinity!

Profile Image for Roger.
72 reviews17 followers
August 24, 2013
This is a well written and very entertaining book, full of interesting facts and observations, and with some challenging puzzles thrown in. It's a great book to dip into and it contains some tricks that you could try out on family or friends. It won't turn you into a mathematician but it might make you think.
203 reviews1 follower
October 10, 2015
Who said mathematics couldn't be fun? This book is very different from what I generally read but I really enjoyed it. The authors show us how maths are everywhere in our daily lives and proceed with understandable - and often funny - explanations. You don't need to be a math genius to get it and you do learn a lot.
Profile Image for Andrew.
224 reviews32 followers
August 13, 2012
Interesting enough, well-written and easy to read.

Although I recognised some of the "popular maths" material as topics I already knew, there were enough surprises here for it to be worth reading.
Profile Image for James Webster.
126 reviews2 followers
August 12, 2013
An interesting and entertaining read which does give some Ah, Aha! and Haha of Maths, as promised. Eastaway doesn't get into detailed e plantations but, even for a non-mathematician like me, it's a bit frustrating always to have to take his word for it.
117 reviews
January 15, 2011
It wasn't gripping reading but there were some interesting and amusing maths tricks and quirks in this book.
Profile Image for Dana.g.
1 review4 followers
Currently reading
July 15, 2011
interesting so far, light and easy style to make you think out of the box.
Profile Image for Voracious.
988 reviews35 followers
March 15, 2012
I enjoyed this, and it's right up D's street. So, recommended for 10 year olds who think maths is really cool. :)
Displaying 1 - 21 of 21 reviews

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