How many coins are there. With two country's on it. One on front and one on the back

This is just another thing that I thought of. The only one I can think of is United States of America and Philippines coins, But that was an administration .

I can think of Portugal and their colonies. For example Mozambique 5 Escudos 1935:

Ho yes I forgot about Portugal

Lots of French colonies do it too.

There's the New Zealand/Bahama's mule 2c coin

Not exactly but you see what I mean !
https://en.numista.com/catalogue/pieces16149.html

1) Occupational coinage. For example, Russian coins for Prussia - 3, 6 and 18 groschen 1759-1761 - contain both names: Russia and Prussia. Other denominations show the monogram of Russian empress, or Russian coat of arms at one side, and the name Prussia at the other.
http://skarbsvit.com/category/numismatics/monetyi-prussii

2) Countermarked coins: when coins of one country were used to produce coins of another country.

Sweden 1 krona 1875-1904. Since Sweden were in a union with Norway the coins from this era bears both the name of Sweden and Norway.

All the French colonies, too. Says Republic of France on one side and colony name on the other: Reunion, Madagascar, St. Pierre and Miquelon, etc.

Quote: "chomp-master"​Lots of French colonies do it too.
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Quote: "Houseofham"​All the French colonies, too. Says Republic of France on one side and colony name on the other: Reunion, Madagascar, St. Pierre and Miquelon, etc.

​Too late

And still on use: Polynesia

Same with New Caledonia, both are the only remaining colonies with separate coinage (as no official coin from W&F and all other overseas territories part of eurozone).