How much is a centavos worth?

Answer 1

If it is a Mexican coin dated 1993 or later, the exchange rate is roughly 1 centavo = 1/10 of a U.S cent. If it's from the 1970s or 80s, the exchange rate was around 1 centavo = 1/10,000 of a cent. (yes, that ridiculously small number was due to inflation.)

Answer 2

20 centavos is 20 cents.