12 - 2 x 6 + 2/2 = ?

Question

I'm in a debate with my brother about the order of operations with this one. Is the answer 1 or -1? 

Please show your work. 

Thanks!

Answer 1

12 - (2*6) + (2/2)

 

The answer is +1, not -1, but I can see your confusion.  PEMDAS might lead you to think, because addition comes before subtraction, that:

 

12 - 12 + 1 = 12 - 13 = -1

 

But that's really 12 - 12 - 1, not 12 - 12 + 1.  The easiest way to think about subtraction is that it's the same as adding a negative number.  So think of it as:

 

12 + (-12) + 1 = 1

 

The answer is 1 no matter whether you do the 12 + (-12) first or the (-12) + 1 first.