The Nisab of Zakah in Paper Currency

Question:
What is the nisab of zakah in paper currency, and how do I know the value of the dollar? If the zakah is in local paper currency, how do I know the nisab?

Answer:
The nisab of silver is one mithqal. The nisab of silver is one hundred and forty mithqals. One hundred and forty mithqals is the nisab of silver. In Saudi Riyals, silver was known as the Saudi silver riyal, which was fifty-six riyals. Fifty-six Saudi silver riyals is the nisab of silver.
Or its equivalent in paper currency. The equivalent of fifty-six means how much is it worth in the market? How much is fifty-six silver riyals worth in the market in paper currency if exchanged? You ask the money changers, and whatever amount it reaches is the nisab of paper currency. The equivalent of the exchange of fifty-six silver riyals is the nisab of paper currency. Yes, because the exchange rate goes up and down. You ask the money changers about it. Yes.