01Why this matters
A shared order makes a written calculation unambiguous. It matters when using a calculator, reading a formula or checking a receipt.
02See it
03Understand it
Order of operations is the shared set of rules for deciding which calculation to do first.
Work inside brackets first, then powers, then multiplication and division from left to right, then addition and subtraction from left to right. Multiplication and division have equal priority. Addition and subtraction also have equal priority. Brackets can deliberately change the order.
04Guided example
Calculate 18 − 2 × (3 + 4).
- Brackets first: 3 + 4 = 7, leaving 18 − 2 × 7.
- Multiplication next: 2 × 7 = 14, leaving 18 − 14.
- Subtract last: 18 − 14 = 4.
05Try it
06Practise it
07Use it in the real world
Three tickets at $12 each plus one $4 booking fee cost 3 × 12 + 4 = $40. The fee is added once, after multiplying the ticket price.
Go a little deeper
A fraction bar groups its entire numerator and denominator. Write (a + b) ÷ c when entering a stacked fraction into a calculator.
08Quick check
09Summary
Order of operations is the shared set of rules for deciding which calculation to do first. Subtract last: 18 − 14 = 4.
Before moving on, explain the worked example in your own words. Use the hint on any question you want to revisit.
10Key idea
Brackets → powers → × and ÷ → + and −
Operations on each shared-priority level are performed from left to right.
Use brackets to specify a different grouping.
Find this in the formula library →