Cambodian Currency Counting

Cambodia carries two monetary units - the local currency Cambodian Riel and, American dollars -without the coins.

This lack of coins means that whatever you buy, be it at a traditional market or at a modern store, your change will be given in both currencies.

The two operate simultaneously however, a headache beckons whenever a vendor sells items in both Riel and dollars.

The vendor will add up the Riel and dollar totals separately, so sometimes you are presented with a bill containing two amounts.
For example, today I bought some plants - the bill: 29,000 Riel and US $8.50.

Thus a dance insues, going over in my head -
4000 Riel = one US dollar, to try and tally it up to match whatever is in my wallet.