Answer :

AL2006
There is a way to work it out with a pencil and paper, but that's too complicated
to try and explain with only text, like we have here.

I don't usually recommend this for things that can be done easily on paper ...
but for square roots, your best bet is to use a calculator.

The square root of 30 does not come out even.  It starts out  5.477225...
and it keeps going and never ends.

The negative of  5.477225... is also a square root of 30.  Every number has
two square roots ... the positive and negative of the same number. 

if you have a calculator put it in as the symbol that goes straight(-) then down(\) then up(/) then straight again. (-)  put in the symbol then 30 and it will give you the square root of 30