I am going to explain why 8/2(2+2) = 16
using PEMDAS
first, parentheses this now becomes 8/2(4)
now, you go from left to right doing division/multiplication. This is where people get confused. some people think you do division first, or maybe multiplication, but no. you go from left to right. same with addition and subtraction
now, this becomes 4(4)
multiply those, and you get 16. easy.