Many schools, especially private ones, want papers that stretch their strongest learners. But a "tough" question that is really a trick, or that tests something outside the curriculum, only measures luck and frustrates everyone. This guide shows how to write questions that are hard because they demand real thinking, while staying inside the curriculum design and fair to every learner.
What makes a question tough but fair
- It stays inside the curriculum design for the grade (or an earlier grade).
- The difficulty comes from thinking, not from obscure facts, confusing language or a hidden trap.
- A well-prepared learner can solve it in the time the marks suggest.
- It has one clearly correct answer, or a marking scheme that credits every valid route.
Six techniques
1. Join two skills in one task
Instead of testing area and money separately, make learners use one to get the other.
Mathematics, Grade 7-8
A rectangular classroom floor measures 8 m by 6 m. Square tiles of side 50 cm cost KSh 120 each. Find the cost of tiling the whole floor.
Answer: Floor area = 8 × 6 = 48 m². One tile = 0.5 × 0.5 = 0.25 m². Tiles needed = 48 ÷ 0.25 = 192. Cost = 192 × 120 = KSh 23,040.
Why it is tough: learners must convert centimetres to metres and divide areas, two places where weaker answers go wrong.
2. Work backwards
Give the result and ask for the starting value.
Mathematics, Grade 8-9
After a 20% discount, a school bag costs KSh 1,440. What was its price before the discount?
Answer: KSh 1,440 is 80% of the old price, so the old price = 1,440 ÷ 0.8 = KSh 1,800. (A common wrong answer is 1,440 + 20% of 1,440 = KSh 1,728.)
3. Find and correct the mistake
Give a worked answer with one error. Learners must spot it, explain it and fix it. This tests understanding far more than a fresh question does.
Integrated Science, Grade 9
Atieno says: "Sodium has atomic number 11 and mass number 23, so it has 23 neutrons." Identify her mistake and give the correct number of neutrons.
Answer: She used the mass number as the number of neutrons. Neutrons = mass number - atomic number = 23 - 11 = 12.
4. Use a new situation for a familiar idea
Learners who memorised an example cannot copy it; learners who understood the idea can apply it.
Agriculture and Nutrition, Grade 7-9
A farmer in a dry area notices that water runs off her sloping shamba during the short rains and the soil is washed away. Suggest two methods she could use to conserve both the soil and the water, and explain how each works.
Possible answers: terracing (breaks the slope so water slows and soaks in); planting cover crops or grass strips (roots hold soil and slow runoff); mulching (protects soil from raindrops and reduces evaporation); digging zai pits or retention ditches (collect water near plants). Award marks for a valid method plus a correct explanation.
5. Ask "which is the best, and why?"
Comparing options and justifying a choice is a higher-order skill and suits every subject.
Social Studies, Grade 8-9
A county wants to reduce traffic jams in its main town. It is considering (a) widening the main road, (b) building a bus park outside the town centre, or (c) a cycle lane. Choose the option you think is best and give two reasons.
Marking: any choice can earn full marks if both reasons are valid and linked to traffic in the town centre. This is how a fair open question is marked.
6. Make language precision count
English, Grade 7-9
Rewrite the sentence without changing its meaning, beginning with the words given: "Although it was raining heavily, the match continued." Begin: Despite ...
Answer: Despite the heavy rain, the match continued. (Also accept: Despite it raining heavily, the match continued.) Do not accept "Despite it was raining", which is ungrammatical.
How many tough questions in a paper?
Keep most of the paper at the expected level so that it still measures what learners have achieved. A good balance is roughly:
| Type of question | Share of marks |
|---|---|
| Recall and straightforward application | about 40% |
| Application in familiar situations | about 40% |
| Challenge (multi-step, new situations, reasoning) | about 20% |
Place challenge questions at the end of each section, and label them if you like, so learners do not lose time on them first.
Fairness checklist
- Is every skill in the question in the curriculum design for this grade or an earlier one?
- Have you solved it yourself, in full, within the time its marks allow?
- Is the language simple enough that the difficulty is in the thinking, not the reading?
- Does the marking scheme give method marks for each correct step?
- For open questions, does the marking scheme accept every valid answer?
- Does any diagram show everything the learner needs, clearly labelled?
Challenge questions, already written and checked. Elimu254 revision books and end-of-term exams include a CHALLENGE section for strong learners, with full answers and marking schemes.
