Chinese seal script is an ancient style of Chinese calligraphy. It evolved organically out of the Zhōu dynasty script, arising in the Warring State of Qin. The Qin variant of seal script became the standard and was adopted as the formal script for all of China in the Qin dynasty. Ever since, its predominant use has been in seals, hence the English name.
Chinese numbers in Mandarin pinyin and hand gestures. This is how one could show different numbers with one's hands in Chinese culture - I used to know all of these when I was little, but have a hard time remembering past 6 now.