Though TimS's method works, I always prefer to find the conversion factor. In this case, you want to know DRK per USD, or how much DRK will 1 USD buy.
Simplify your BTC/USD factor
0.01724138 BTC .00172414 BTC
-------------- = -------------
10 USD 1 USD
Set up the conversion factor you are targeting. In this case, we want DRK on top and USD on bottom
.00172414 BTC 1 DRK
------------- x -------------
1 USD .01766900 BTC
The BTC unit cancels out and we are left with:
.00172414 1 DRK .0975798290 DRK
--------- x ----- = ---------------
.01766900 1 USD 1 USD
So 1 USD will buy you about a tenth of 1 DRK. Notice I added two extra decimals than the typical 8; this will account for up to three digit values that you want to multiply the factor by, because you loose decimals with every 10th.
Now you have the conversion factor and you can multiply it by any USD amount (that I assume you are considering investing) to get exactly how much DRK that will work out to. In this case, you said 10 USD so
.0975798290 * 10 = .9757982900
We round that off to eight decimals and you get your amount. 10 USD will buy .97579829 DRK.