Most marks are lost to the same handful of mistakes. Fix these and you'll usually pick up 10–15 marks across both papers.
1. Not showing working
The CAPS memo awards method marks even when the answer is wrong. No working = no marks.
2. Dividing by x and losing a root
If x = 0 could be a solution, factor it out instead of dividing. Example: x² = 3x. Dividing by x gives only x = 3; factorising x(x − 3) = 0 gives x = 0 or x = 3.
3. Sign errors in the quadratic formula
Always write a, b, c down before substituting. For 2x² − 5x − 3 = 0, b = −5, so −b = 5 and b² = 25, not −25.
4. Forgetting the +k·360° in trig general solutions
Every general solution needs the period term — usually +k·360° or +k·180°. Example: tanθ = 1 gives θ = 45° + k·180°, k ∈ ℤ.
5. Confusing 'mutually exclusive' with 'independent'
Mutually exclusive means they can't both happen. Independent means one doesn't affect the other. In symbols: mutually exclusive means P(A and B) = 0; independent means P(A and B) = P(A) × P(B).
6. Using annual i and n when interest compounds monthly
Divide the rate by 12 and multiply the years by 12. Example: 9% p.a. compounded monthly for 3 years uses i = 0,09/12 and n = 36.
7. Not labelling sketches
Intercepts, turning points, asymptotes — all earn marks.
8. Skipping units in measurement and 3D
A correct answer without units can lose a mark.
9. Misreading the question
Always underline the verb: 'sketch', 'prove', 'hence', 'show that'.
10. Not using past papers
Nothing predicts your final mark better than how many you've written. When a question stops you, snap it into Snap&Learn — you'll get a CAPS-aligned step-by-step explanation in seconds, and your first three AI solutions are free.
Bonus: rounding too early
Rounding intermediate values, especially in finance and trigonometry, can change the final answer and cost the accuracy mark. Store values in your calculator's memory and round only the final answer, to the number of decimals the question asks for.
How to fix them in a week
- Pick the three mistakes on this list you make most often.
- For each one, find five past-paper questions where it could happen.
- Do them slowly, checking for that mistake at every step.
- Repeat the set a week later under time pressure.