PEMDAS
It stands for "Parentheses, Exponents, Multiplication and Division, and Addition and Subtraction".
This tells you the ranks of the operations: Parentheses outrank exponents, which outrank multiplication and division (but multiplication and division are at the same rank), and these two outrank addition and subtraction (which are together on the bottom rank).
When you have a bunch of operations of the same rank, you just operate from left to right. For instance, 15 3 4 is not 15 12, but is rather 5 4, because, going from left to right, you get to the division first.
If you're not sure of this, test it in your calculator, which has been programmed with the Order of Operations hierarchy......
"GermanGilbert" wrote: