Question

what is the last digit of 6power 100

Answer 1

ans is 6 
this is beacause
6^1=6
6^2=36
6^3=216
.
.
.
6^100=........6
units digit is always 6 for any power of it other than 0
therefore ans is 6

Answer 2

The unit digit is always 6. 

So unit digit of 6^100 is 6.

The reason is below.