Quote:
Originally Posted by susanlai89
6÷2(2+1)=?...some said 1 some said 9...
I said 6÷2(2+1)=6÷4+2=3/2 + 2= 7/2
and for
6÷2(1+2)=?...some said 1 some said 9...
the solution should be 6÷2(1+2)=6÷2+4=3+4=7

In any form of math this answer is clearly wrong since the 6 is outside the brackets, it has to operate on everything within the brackets.
The simple answer is that order of operation dictates that;
terms inside parenthesis
exponents and roots
multiplication and division
addition and subtraction
This means that, step one
Add 1+2 = 3
Step 2 there are two ways to go here,
V1.0 if you subscribe to the rule that multiplication and division have no precedence then you operate from left to right.
6/2 = 3
3*3 = 9
V2.0 If you subscribe to the rule that PEMDAS = Parenthesis > exponents > multiply > divide > add > subtract
2*3 = 6
6/6 = 1