How do you simplify a surd?

If you have a surd, for example root27, in order to simplify it you need to find factors of it which are square numbers. Multiplying surds is like regular multiplication, for example, root27 = root9 x root3. Here, 9 is a square number. We know that the square root of 9 is equal to 3, so therefore root27 = 3 x root3, which can be written as root27 = 3root3