Ok, the tenth can be found 1 decimal place to the right of the decimal points, in this number, the tenth place would be:
659.
1649
(tenth place highlighted in bold)
Since there's a 6 next to the one, this means that we would round up. So, 659.1649 rounded to the nearest tenth would be:

Let me know if you have any more questions regarding this problem!
Thanks!
-TetraFish