What do the square brackets mean in $[5-(6-7(2-6)+2)]+4$? While watching a youtube video about a Simpsons math episode at 1:27 there's a puzzle that includes square brackets.
$$[5-(6-7(2-6)+2)]+4$$
Apparently the answer is $-27$ which I can't figure out how to arrive at that answer. I've Googled that the square brackets mean intervals. But then I don't understand the context of this question as surely an interval should be two numbers separated by a comma?
How do you arrive at $-27$?

Here square brackets means parentheses but not interval. While solving these type of questions first solve the expression in ( ) next solve the expression in flower bracket i.e. { } next sole the expression on square brackets i.e. [ ]. Please don't take [.] as greatest integer function. In this problem we must start computing from inner most bracket to outwards.
$$[5-(6-7(2-6)+2)]+4$$
$$=[5-(6+28+2)]+4$$
$$=[5-36]+4$$
$$=-31+4$$
$$=-27$$
