1. HAT COLORS AND HAMMING CODES 1
2. TWENTY BOXES AND PERMUTATIONS 17
3. THE DOVETAIL TRICK AND RISING SEQUENCES 33
4. ANIMAL STICKERS AND CYCLIC GROUPS 55
5. OPERA SINGERS AND INFORMATION THEORY 73
6. ANIMAL MATCHING AND PROJECTIVE GEOMETRY 93 6
7. THE EARTH AND AN EIGENVALUE 109
8. THE FALLEN PICTURE AND ALGEBRAIC TOPOLOGY 123
A. WHAT DO WE MEAN WHEN WE WRITE …? 139
B. WHAT IS … 143
C. CHAPTER-SPECIFIC DETAILS 157
REFERENCES 171
INDEX 175