https://en.numista.com/numisdoc/index.php?cat=4
That is a date converter for various countries.
Found in Numisdoc at the top of this page.
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https://en.numista.com/catalogue/pieces922.html
10 Yen 39 (1964) Y# 73a
The date is from the symbols under the large 10 numeral >
The first four are of an Emperor whose reign started in 1926
The next three symbols are 3 10 9 which is 3x10+9
The last symbol is 'date'
As 1926 is year 1 then for calculations add to one year earlier
i.e. 1925 plus 1 = 1926 date. Hence 1925+39 makes 1964
for your coin, which is from
Japan not China.
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The converter reads
w๒๔๙๓
Result : Année 2493 de l'ère bouddhique = 1950
Assuming I read the blurred characters correctly.
This coin has images to match that date ...
https://en.numista.com/catalogue/pieces11038.html
5 Satang - Rama IX 2493 (1950) Y# 72





Larger date numerals, from the converter page.

The symbol on left of emblem reads 5 numeral/denomination.
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Well, that is what I think those two coins are. Hope it helps.