Circle & Hidden 9

‘9’ is the biggest number in the digits {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}.

9 is reserved for the ancient Chinese Emperors whose robes were sewn with 9 dragons, and the palace roof top decorated with 9 dragons too.

http://mp.weixin.qq.com/s?__biz=MzA3MjE0ODAzMw==&mid=204651538&idx=1&sn=33027a35921519fe42c647e1f5a4dadc&scene=1&from=groupmessage&isappinstalled=0#rd