Books ·HTML edition
Number Puzzles
Fifty classic puzzles, with worked solutions
50 chapters · About the book
- 1 The Suppressed Digit
- 2 Brandy and Wine
- 3 The Missing Term
- 4 The Club of Six
- 5 One Hundred, and One
- 6 A Stroke of Genius
- 7 Two Games of Chance
- 8 Dots in Triangles and Pyramids
- 9 Jack and Jill
- 10 Square Palindromes
- 11 Four Consecutive Numbers
- 12 Divisibility by Seventy-Three
- 13 Pick Five, Always Sixty-Five
- 14 Cancelling, and a Cube Trick
- 15 A Pandigital Divisible by Eleven
- 16 Casting Out in Threes
- 17 A Prime Number of Rails
- 18 Nine Digits, the Unit Fractions
- 19 A Father’s Fair Division
- 20 A Will of Diamonds
- 21 Four Weights for Forty
- 22 One Light Column
- 23 The Ages of Three Children
- 24 Numbers Made of Their Own Factorials
- 25 Ten in a Row, None Prime
- 26 A Power of Every Kind
- 27 His Age in a Square Year
- 28 One Before, One After
- 29 A Number That Counts Itself
- 30 The Coconuts and the Monkey
- 31 The House in the Middle
- 32 Numbers That Reappear in Their Squares
- 33 A Cube and a Square
- 34 Threading Thirty-One and Seventy-Three
- 35 Eight Queens
- 36 Weighed Two at a Time
- 37 Squares of All the Digits
- 38 Every Digit, Every Divisor
- 39 Adding a Million Numbers at Once
- 40 Matched at Every Power
- 41 ADE plus ODO
- 42 What the Post Office Cannot Make
- 43 The Greatest with Three Digits
- 44 The Only Magic Hexagon
- 45 Three Urns
- 46 One Hundred from Nine Digits
- 47 A Thousand Pounds in Bags
- 48 An Ancient Magic Square
- 49 The Counting Competition
- 50 Bananas and Pears