Your 20 centavos from Cuba catalogs for $8 US dollars in average circulated condition, half that if worn, twice that if well preserved. See if you have one dated 1932; that's the good date in the series, worth about $50 in average circulated condition. All other dates carry the $8 value, with the more modern dates worth a little less than the older dates.

There are some nuances with these coins that may get collector juices flowing.
The 1915 20 centavos was made with both a fine reeding and a coarse reeding on the edge. Also, it was made both with a low relief star and a high relief star! That means that just for 1915, there were four different 20 centavos coins.
The 'high relief star, fine reeding' and 'low relief star, coarse reeding' varieties are common coins. However, if you have one where the differences are switched around, you have a valuable coin.

A 'low relief star, fine reeding' 1915 20 centavos coin catalogs for $50 in average circulated condition.
A 'high relief star, coarse reeding' 1915 20 centavos coin catalogs for $150 in average circulated condition.

If you have a common date coin worn down to a frazzle, it will only be worth value of the silver it contains. These coins weigh 5 grams and are made of .900 pure silver. At 0.1447 troy ounces of silver per coin, and silver prices of around $24 per troy ounce, that works out to just about $3.50 per coin.

Also, be sure you understand what 'catalog' means. Use the Important Terminology link at the upper left.