The PEMDAS rules that state the order in which the operations in an expression should be solved are. Order of Operations Includes Parenthesis. We start with the Multiplication and Division working from left to right.
Then multiply 1 by 2 yielding 2.
Calculators that use reverse Polish notation RPN also known as postfix notation use a stack to enter expressions in the correct order of precedence without a need for parentheses or any possibly model-specific order of execution. When doing computations always follow the order of operations and always perform the operations according to the following rule. P Parenthesis Page 1 of 4. Do inside the parenthesis first.