fourth root of 625

Ninja has given you a good answer.   Thanks Ninja.

I would just like to add that 

$$\sqrt[4]{625} = 625^{1/4} \quad or\:\: 625^{0.25}$$

So if you want to do it on cqalculator, this is how you would enter it.  

625^(1/4)=

$${{\mathtt{625}}}^{\left({\frac{{\mathtt{1}}}{{\mathtt{4}}}}\right)} = {\mathtt{5}}$$

⁴√625

This is asking, "what times itself 4 times equals 625?"

First we can figure out what times itself will equal 625.

It turns out 25*25=625.

Now we have that the square root of 625 is 25. We now need to find the square root of 25.

It turns out this is 5, because 5*5=25.

So to 4th root of 625 is 5.

To check this, multiply 5*5*5*5 and it should equal 625.

5*5*5*5

25*25

625

There we go, it works.