The 10-sided gaming die is useful for generating random numbers from 1 through 10 but can also be combined with one or more d10s to generate numbers between 1 and 100, 1 and 1000, and so on.
Commonly numbered from 0 through 9 instead of 1 through 10, the 0 can be read as either a zero or as a 10. This is what allows d10s to be combined to generate percentile results. If you use two d10s, each one a different color, and specify one die to display the ones results and one die to display the tens results, you can generate numbers between 1 and 100. For example, if you roll a 6 on the "tens" die and 3 on the "ones" die, the result would be 63. A double-zero result on the two dice is generally considered to signify 100.
You can also use our specialty "tens" dice instead of two standard d10s to generate percentile rolls, which makes it so you don't have to remember which die is the tens and which is the ones.