Because the dimes were minted when coins were still made with actual silver, the value will fluctuate along with silver prices. Fortunately, silver is doing well right now and expected to go up. A dime in good condition will currently fetch around $1.40.
The value of a 1947 U.S. dime depends on where it was minted and the condition it is in. It is worth maybe two dollars, unless it is in proof or perfect condition, which would probably be worth up to a hundred!