Find the units digit of $16^{17} \times 17^{18} \times 18^{19}$.
The units digit of 16^17 is 6, the units digit of 17^18 is 3, and the units digit of 18^19 is 2, so the units digit of 16^17*17^18*18^19 is the same as the units digit of 6*3*2, which is 6.
+53 
