Question

What is the last digit of $6^{100}$?

Answer 1

Find the last digit of $6^{100}$.

$6^m=6$ for any power $m$.
Look at the pattern below:

$\begin{array}{rcl}{6}^1& =& 6\\ 6^2& =& 36\\ 6^3& =& 216\\ & & .\\ & & .\\ & & .\end{array}$
So, the last unit digit is always $6$ for any power $m$.
Hence, the last digit of $6^{100}$is $6$.