Common Ways to Lose Marks
Marks You're Leaving on the Table
These are the most common ways students lose marks unnecessarily. Avoid these traps and watch your grade improve.
Trap 1: Not Showing Working
The Problem: "I can do it in my head" is not a valid excuse when the paper says "show your working."
How It Loses Marks: A 4-mark question with just the final answer:
- Correct answer: 4/4 marks
- Wrong answer: 0/4 marks (no method marks possible)
The Fix: Every calculation with 2+ marks needs visible working. Even if your answer is wrong, method marks can be earned.
Trap 2: Wrong Degree of Accuracy
The Problem: The question asks for 2 decimal places, you give 3. Or asks for 3 significant figures, you give an exact answer.
Examples That Lose Marks:
- Asked for "2 d.p." → gave 3.142 instead of 3.14
- Asked for "to the nearest 10" → gave 47 instead of 50
- Asked for "3 s.f." → gave 4560 instead of 4560 (this one's actually fine!)
The Fix: Underline the accuracy requirement when you read the question. Check your final answer matches before moving on.
Trap 3: Forgetting Units
The Problem: Your answer is numerically correct but you forgot "cm" or "m²" or "£".
Common Unit Mistakes:
- Area without square units
- Volume without cubic units
- Money without £ or pence
- Speed without km/h or m/s
The Fix: Write units from the start of your calculation. If you write "$A = \pi r^2$ = ..." and finish with units, you won't forget.
Trap 4: Perimeter vs Area vs Volume
The Problem: You calculate the wrong measurement. Perimeter when asked for area. Circumference when asked for diameter.
Why It Happens:
- Rushing
- Not reading carefully
- Mental autopilot
The Fix: Before calculating, write down what you're finding: "Area = ..." or "Perimeter = ..."
Trap 5: Incomplete Answers
The Problem: Multi-part questions where you answer (a) but forget (b) or (c).
Why It Happens:
- Questions span multiple pages
- You got stuck on one part and forgot to return
- Hidden parts at the bottom of the page
The Fix: At the end of the exam, quickly flick through every page. Check every question has something written.
Trap 6: Calculator Mode Errors
The Problem: Your calculator is in radians or gradians instead of degrees.
Result: Every trigonometry answer is wrong. Often spectacularly wrong.
The Fix: Check before EVERY exam. sin(90) should equal 1.
Trap 7: Giving Only One Solution
The Problem: Quadratic equations have two solutions. The question asks for all of them. You give one.
Similar Issues:
- Listing only some values in a range
- Finding only one angle when there are two in 0-360°
- Missing negative solutions
The Fix: Look for "all values," "all solutions," or when you expect multiple answers (quadratics, ±).
Trap 8: "Hence" Means Use Your Answer
The Problem: A question says "Hence find..." and you ignore your previous answer and start from scratch.
Why It's Bad:
- Wastes time
- Might get a different (wrong) answer
- Shows you don't understand the structure
The Fix: "Hence" = use what you just found. Look at your answer to the previous part.
Trap 9: Ratio Errors
The Problem: Confusing "ratio 2:3" with "fraction $\frac{2}{3}$."
Example Error: "Divide £100 in ratio 2:3" ❌ Wrong: $\frac{2}{3} \times 100 = £66.67$ ✅ Right: 2 parts = £40, 3 parts = £60
The Fix: For ratio questions, always find the total number of parts first.
Trap 10: Graph Reading Errors
The Problem: Misreading scales, especially when they don't go up in 1s.
How Marks Are Lost:
- Reading 25 instead of 250 (scale is in tens)
- Plotting at wrong gridlines
- Interpolating incorrectly
The Fix: Before reading or plotting, consciously check: "What does each square represent?"
Trap 11: Leaving Questions Blank
The Problem: Writing nothing because you don't know the complete answer.
The Truth: A blank answer = 0 marks. Always. A partial answer = possible marks.
The Fix: Write anything relevant: formula, diagram, first step, what you would do. Examiners want to give marks.
Final Check Quiz
Before submitting, ask yourself: ✓ Did I answer all parts of every question? ✓ Are my units correct? ✓ Did I round to the right accuracy? ✓ Did I show working for every question worth 2+ marks? ✓ Is my calculator in degrees mode?