Calculator Skills
Order of Operations on Your Calculator
A scientific calculator follows the order of operations for you, but only if you enter the expression the way you mean it.
Use brackets to be safe
The calculator does multiplication and division before addition, and powers before that. When a numerator or denominator has several terms, wrap it in brackets, a missing bracket is one of the most common calculator errors in the exam.
A worked keystroke sequence
- Enter 6 + 12 ÷ 3 × 2 exactly as written, then press = .
- The calculator applies ÷ and × before +, and works left to right, so 12 ÷ 3 = 4, then 4 × 2 = 8, then 6 + 8 = 14.
- Now enter ( 6 + 12 ) ÷ 3 and press = . The brackets force the addition first: 18 ÷ 3 = 6.
- The digits are identical, but the order changed the answer from 14 to 6, which is why brackets are not optional when you mean the addition to come first.
The dividing-by-a-product trap
A common slip is typing 24 ÷ 2 × 3 when you meant to divide by the whole product 2 × 3. The calculator reads it left to right as (24 ÷ 2) × 3 = 36, but you wanted 24 ÷ (2 × 3) = 4.
Whenever the denominator is more than one term, wrap it in brackets. Reading your line back and asking what is really underneath the fraction bar catches this before it costs a mark.
Source:SPM: Format Pentaksiran mulai 2021, Matematik (1449)
Frequently asked questions
Does the calculator follow BODMAS on its own?
Yes, a scientific calculator applies the order of operations automatically, brackets, then powers, then multiply and divide, then add and subtract. The catch is that it obeys exactly what you type, not what you meant.
If your typed line does not match the expression in your head, the correct order still gives a wrong answer.
When do I actually need to add brackets?
Add brackets whenever a numerator or denominator has more than one term, around a whole sum before dividing, and around a negative number you are squaring. When in doubt, add the brackets, they never change a correct expression, but they rescue an ambiguous one from being read the wrong way.
How can I check I entered a long expression correctly?
Use the cursor to scroll back along the entered line and read it against the question before pressing equals. Then do a rough mental estimate of the size of the answer.
If the display is far from your estimate, the most likely cause is a missing bracket or a misplaced operation.