Guide · For SS 2 – SS 3 students · 6 min read
Your calculator for WASSCE Maths: choosing it and using it well
What WAEC allows, which features are worth having, how to avoid the classic calculator mistakes (wrong mode, missing brackets, early rounding), and when to put the calculator down and write the working.
By the MathPlug team, Reflex System · Published
A calculator will not pass WASSCE Mathematics for you, but a calculator you know well can save you time and protect you from careless errors. A calculator you do not know well can do the opposite: wrong mode, missing brackets, or an answer rounded too early can quietly cost you marks.
This guide covers what you are allowed to take into the hall, the features worth having, the habits that make your answers accurate, and the times when the calculator should stay on the desk.
What WAEC allows in the exam hall
WAEC permits calculators that are non-programmable, silent and cordless. Phones are not allowed in the hall at all, even switched off, so you cannot use a phone as a calculator. If you are unsure whether your calculator is acceptable, ask your school's examinations officer well before the exam, not on the morning of the paper.
Mathematical tables are part of the syllabus. Questions can expect you to read values such as logarithms or trigonometric ratios from tables. So even if you use a calculator for most of your work, practise reading the tables too. Our using log tables lesson shows you how.
Features worth having
You do not need an expensive calculator. A standard scientific calculator that meets WAEC's rules is enough. Check that yours can do these things:
| Feature | What it helps with |
|---|---|
| Fraction key | Working with and simplifying fractions like 34 + 25 |
| Powers and roots | x2, x3, any power, square roots and cube roots |
| sin, cos, tan and their inverses | Trigonometry, bearings, angles of elevation |
| Brackets | Keeping the order of operations correct |
| Statistics mode | Checking a mean or standard deviation |
| Answer memory (Ans) and memory keys | Carrying full accuracy from one step to the next |
| log and 10x | Checking logarithm work |
💡 Tip: Use the same calculator for all your revision as the one you will take into the exam. Every model puts keys in slightly different places, and the exam hall is not the place to learn a new one.
DEG and RAD: the mode that catches people
Scientific calculators can measure angles in degrees (DEG) or radians (RAD). WASSCE General Mathematics works in degrees, so your calculator must be in DEG mode for trigonometry. Most calculators show a small D or DEG on the screen.
A quick test of your calculator's angle mode.
- Type sin 30 and press equals.
- In DEG mode you get 0.5, which is correct for sin 30°.
- In RAD mode you get about −0.988, because the calculator thinks you mean 30 radians.
- If you ever see an unexpected answer in trigonometry, check the mode first.
Make this test part of your routine at the start of every trigonometry practice and on the day of the exam.
Brackets, order of operations and negatives
A calculator follows the order of operations strictly. It does exactly what you type, not what you meant.
- To work out 12 + 84, you must type (12 + 8) ÷ 4 = 5. Typing 12 + 8 ÷ 4 gives 14, because the calculator divides first.
- To square a negative number, use brackets: (−3)2 = 9. Typing −32 gives −9, because the calculator squares the 3 and then makes it negative.
- For a long fraction, put brackets around the whole top and the whole bottom: 5.6 + 2.41.6 × 2 is (5.6 + 2.4) ÷ (1.6 × 2) = 2.5.
Our study tip on order of operations goes through the rules if you need a refresher.
Keep full accuracy with the answer memory
One of the most common ways to lose marks is to round a number in the middle of a calculation and then carry the rounded value forward. The final answer drifts away from the correct one. Instead, use the Ans key (or the memory keys) to carry the full value into the next step, and round only at the very end.
In a right-angled triangle, the hypotenuse is 12 cm and one angle is 35°. Find the side opposite the 35° angle, correct to 2 decimal places.
- Opposite = 12 × sin 35°
- sin 35° = 0.573576... (keep it on the screen; don't write it down rounded)
- Opposite = 12 × 0.573576... = 6.88292...
- Answer: 6.88 cm (to 2 decimal places)
- If you had rounded sin 35° to 0.57 first, you would get 12 × 0.57 = 6.84 cm, which is wrong at the second decimal place.
On paper, you can still write the intermediate values with a few extra digits so the examiner can follow your method. Just make sure the calculator keeps the full value.
Check with an estimate
A calculator answer is only as good as what you typed. A quick estimate catches a missed key or a misplaced decimal point.
Ngozi works out 48.7 × 21.3 and gets 1037.31. Is it reasonable?
- Round each number to one significant figure: 48.7 ≈ 50 and 21.3 ≈ 20.
- Estimate: 50 × 20 = 1000
- 1037.31 is close to 1000, so the answer is reasonable. If she had seen 103.731 or 10373.1, she would know to type it again.
When not to use the calculator
- When the question asks for working. In Paper 2, marks are given for the method. A calculator answer with no steps shown can earn very little. Write the formula, substitute, and show each step.
- When an exact answer is needed. If a question says "leave your answer in surd form", √8 must be written as 2√2, not 2.828. Similarly, "in terms of π" means π stays in the answer.
- When the numbers are simple. Writing 3 × 4 on the calculator takes longer than knowing it, and simple mental arithmetic keeps your brain quick for Paper 1.
- When a question tests a skill directly, such as simplifying fractions, converting number bases or using tables. Show the method even if you check with the calculator.
Practical habits before the exam
- Practise every past paper with the calculator you will use on the day.
- Learn where the fraction, power, root, Ans and statistics keys are, without searching.
- Check the angle mode (DEG) at the start of each paper.
- Fit new batteries a few weeks before the exam, and carry a spare if your calculator uses replaceable ones.
- Clear the memory before the exam so old values cannot confuse you.
Questions students ask
- What calculator is allowed in WASSCE?
- WAEC allows non-programmable, silent and cordless calculators. Phones are not allowed in the exam hall. If you are unsure about your calculator, ask your school's examinations officer before the exam.
- Should my calculator be in degrees or radians for WASSCE Maths?
- Degrees. Set it to DEG mode. A quick check is sin 30, which should give 0.5.
- Do I still need to learn mathematical tables if I have a calculator?
- Yes. Mathematical tables are part of the syllabus, so practise reading log and trigonometric tables as well as using your calculator.
MathPlug is not affiliated with WAEC, NECO or any state examination board. Exam details here come from published syllabuses and exam schemes; always check the instructions on your own question paper and your school's timetable. Spotted something to correct? Tell us.