Believe it or not the Chinese characters shown below are all variants forms of the ’same’ character.

Variant forms of the complex Chinese character for one

The character in question is 壹 (yī) - the complex form of ‘one’, which is used on banknotes, coins and cheques. Well actually the first one is a version of 一, the simple from of ‘one’.

The first two characters come from this site, which includes a number of other rare and unusual Chinese characters. The only one of them I’ve seen ‘in the wild’ is the Shanxi noodle one (no. 2), which appears in many Chinese restaurants in the UK.