★ listed in the Excellent Books Recommended for Teenagers in the Summer of 2020 by Shanxi Provincial Press and Publication Bureau
★ Every number is a symbol. It originated in ancient India, spread from Arabia, and now it is gradually informatized.

Have you ever found yourself surrounded by numbers? Whether it’s at school, at home, or anywhere else, there are always all kinds of numbers surrounding you, and you can’t escape.
Math class is full of numbers: natural numbers, addition, subtraction, multiplication and division, area calculation...
There are also numbers in the Chinese class: “Two orioles sing in a green willow, and a group of egrets ascend to the sky. Through the window you can see snow of thousands of autumns in the Xiling Mountains, and out of the door you can see ships from the Eastern Wu ten thousand miles away.” Without numbers, there is no mood at all.
This book will take you into the fantastic world of numbers.

Zhang Xiaodong is the head of the national high school science lecturer group, a popular science consulting expert for CCTV’s Is It True and other columns, and a lecturer of courses from the national Open University and popular science lectures.

1 Numbers are a human game 1
2 55 scratches on a wolf bone 4
3 The development of ancient Chinese mathematics 7
4 How much money does China have? 10
5 Numbers about raising the national flag 13
6 Breaking Zu Chongzhi’s record 16
7 March 14—International Mathematics Festival 19
8 Roman numerals 22
9 Ancient Egyptian mathematics 25
10 The golden section and its application 28
11 The world’s first female mathematician 31
12 The origin of the fiscal “deficit” 34
13 How many kinds of numbers are there? 37
14 Yin and yang, Eight Trigrams and computer 40
15 Numbers in the computer 43
16 Numeral systems 46
17 Thales—the earliest mathematician 49
18 The “Nobel Prize” of mathematics 52
19 Mysteries left behind by the Egyptian pyramids 55
20 History of the Mathematical Olympiad 58
21 Mathematical elements in Leonardo da Vinci’s creations 61
22 Does the solar term belong to the lunar calendar or the solar calendar? 64
23 Number Idioms 67
24 King’s rice 70
25 Tian Ji's wisdom and integrity in horse racing 73
26 Mathematical geniuses in the animal kingdom 76
27 What is the “Millennium Bug”? 79
28 A talent becomes a talent finder 82
29 A mathematician who failed math exams 85
30 Gauss—the Prince of Mathematics 88
31 Your digital identity 91
32 Magical “0” 94
33 China’s abacus and its application to the World Heritage 97
34 Two incomings of Western mathematics to China 100
35 Operation symbols in four arithmetic operations 103
36 The origin of fractions 106
37 A year as a metaphor for the universe 109
38 A day as a metaphor for human beings 112
39 Music and numbers 115
40 Stories of 3, 4, and 5 118
41 Games of number 9 121
42 Orders of magnitude 124
43 Is there a maximum number? 127
44 Numbers to remember 130
45 Numbers from the body 133
46 Digital technology 136
47 What is fuzzy mathematics? 139
48 The jewel in the crown of mathematics 142
49 East and West preferences for numbers 145
50 Mathematical problems in World War II 148
51 The world is connected 151
52 Changes in the world center for mathematics development 154