Contents i
INTRODUGTION page 7 &
I. THE MAKING OF NUMBERS 9 i
2. SERIES—SHAPES AND SQUARES 17
3. SERIES (conf.)—CUBES AND OTHERS 27 i
4. ‘DIGITAL’ ROOTS 38 ;:g_'
5. ‘PRIMES AND FACTORS’ 46 ;
6. DIVISIBILITY 64 %
7. MULTIPLICATION WITH A DIFFERENCE 72 l%
8. LOGARITHMS AND TRIGONOMETRICAL
RATIOS 81 *‘f
9. PERFECT NUMBERS AND SOME
ODDITIES 87 g
1I0. RECURRING DECIMALS 97 ?
II. CONGRUENCES 108 ‘
I2. IRRATIONALS, IMAGINARY NUMBERS :
AND CONTINUED FRACTIONS 112 i
13. PSEUDO-TELEPATHY 125 %
14. FALLACIES 135 E
I5. MAGIC SQUARES 145 %
16. NUMBER MYSTERY 156 3
Appendices
I. PASCAL’S TRIANGLE AND THE
BINOMIAL THEOREM 161

2. TRIANGULAR NUMBERS AND COM-
BINATIONS 165

5

3 g

PES PO P e