Roosevelt dimes have been around for a long time. They have never caught on very well with collectors, and most of them carry low value. As the US dollar weakens and the price of silver goes up, dimes dated before 1965 acquire more and more value. Pre-1965 dimes are made of 0.0723 troy ounces of silver, so multiply that number by the current price of silver, and you have the value of a pre-1965 dime. At the time of this writing, silver is at $28 US dollars per troy ounce (look it up on kitco.com, it changes every day), so a pre-1965 Roosie is worth 0.0723 x 28 = $2. Not bad. If you have a roll of 50 pre-65s, it is worth $100. Wow!
Post-1964 dimes are made of copper and nickel. They are worth, well, one dime.
There are only two *good dates* in the Roosevelt series: the 1949 and 1949S. (The dime in our picture has a D mint mark on the reverse. A 1949D dime is not a *good date.*) For circulated coins, once you figure the value due to silver content, add another $1 for a 1949 coin and another $2 for a 1949S coin. If you can find fully uncirculated examples of a 1949 or 1949S, the values start to approach $20.