If I want to cancel a square a.k.a 4^2 do I multiply or add it to the square route of said number (4 here)
You don't add or multiply the square root, you 'take' the square root.
I.e you may have and you want to find
which is the same as
now you can see you can take the square root of both sides.
which in turns yields
As square and square root are opposites.
Now go ahead and change the world!