Ok, it says -(-10) is 10, which I get, but why does -|-5.2| = -5.2? I thought || were the same as ()
You don't get square brackets unless you want to show a bracket of a bracket in which case a square bracket looks neater so...
e.g.
(In which case you are saying, find the value of the brackets first then do the arithmetic outside the square bracket).
A square bracket doesn't change the value of the number so it is the same as curvy bracket.
EDIT: It is not the same as modulus =