Find the last non zero digit of 28!. 
Find the last non zero digit of 28!.

It is very hard to multiply and find the last nonzero digit. I just wanna know that, is there any easy technique to solve this type of problem?

Perhaps a small reduction in the calculations in other answers.  First, we use the standard technique for finding the power of a prime which divides a factorial:
$$\Bigl\lfloor\frac{28}{5}\Bigr\rfloor+\Bigl\lfloor\frac{28}{25}\Bigr\rfloor
  =5+1=6$$
so $5^6$ is a factor of $28!$ (and $5^7$ is not), and likewise
$$\Bigl\lfloor\frac{28}{2}\Bigr\rfloor+\Bigl\lfloor\frac{28}{4}\Bigr\rfloor
  +\Bigl\lfloor\frac{28}{8}\Bigr\rfloor
  +\Bigl\lfloor\frac{28}{16}\Bigr\rfloor=14+7+3+1=25\ ,$$
so $2^{25}$ is a fcator of $28!$.  Therefore $28!$ ends with $6$ zeros and we need the last digit of $28!/10^6$.  Simplifying modulo $10$, we have
$$2^\equiv2^5\equiv2^9\equiv2^{13}\equiv2^{17}\ ,\quad 3^4\equiv1\ ,\quad
  7^4\equiv1\ ,\quad 9^2\equiv1\ ;$$
cancelling $2$s and $5$s and reducing the resuts modulo $10$ gives
$$\eqalign{28!/10^6
  &\equiv2^{19}1.1.3.1.1.3.7.1.9.1.1.3.3.7.3.1.7.9.9.1.1.1.3.3.1.3.7.7\cr
  &\equiv2^3.3^8.7^5.9^3\cr
  &\equiv8.1.7.9\cr
  &\equiv4\ .\cr}$$
