Uncirculated 10 air stamp what is it worth?

We don't know what year your stamp was made. There were many different 10¢ airmail stamps. If it has a Liberty Bell picture it's worth around 50¢. If he has an airplane it's worth around $3.00 to $8.00 depending on which picture it has. If it's only a red stamp that says Air Mail it isn't worth very much, maybe 25¢. Go to a book store and look at a Stamp Price Guide to find the same one as you have.