Conventions that determine the order in which we operate when finding the value of a sequence of operations.

The order that we must follow is:

(1) Solve operations in parentheses (P)

(2) Solve exponents (E)

(3) Solve multiplication and division from left to right (MD)

(4) Solve addition and subtraction from left to right (AS)

(1) Solve operations in parentheses (P)

(2) Solve exponents (E)

(3) Solve multiplication and division from left to right (MD)

(4) Solve addition and subtraction from left to right (AS)

A mnemonic device to remember this order is the acronym PEMDAS.

### Example

\(\begin{aligned}

28 – 3(12 ÷ 4) – 4^{2} &= 28 &&– 3 × 3 &&&– 4^{2}\\

&= 28 &&– 3 × 3 &&&– 16\\

&= 28 &&– 9 &&&– 16\\

&= 19 &&&– 16\\

&= 3

\end{aligned}\)