Question 1 of 35
Today is Tuesday. What day was it yesterday?
🔬 Science · Class 4 · 2026-27
SOF ISO Class 4 free mock test and sample paper
A full ISO Class 4 practice paper: 35 questions for 40 marks in 60 minutes, in the same 3 sections and order as the SOF paper. Take it here with an instant score — no login, no sign-up — or print it with an OMR sheet and the answer key. Free, with no ads.
- Questions35
- Marks40
- Time60 min
- Sections3
The paper
Tap an answer for each question. The 60-minute clock starts at your first answer; press Finish and mark at the bottom when you are done, and every answer is explained.
Section 1 — Logical Reasoning · 5 × 1 mark
- Question 2 of 35
If these words are arranged in the order they appear in a dictionary, which word comes 2nd?
Bride, Brisk, Bring, Bridge, Brief
- Question 3 of 35
Which number comes next in the series?
- Question 4 of 35
Three of these numbers belong to a group. Which number does not belong?
- Question 5 of 35
Which letter comes next in the series?
O, Q, S, U, W, ?
Section 2 — Science · 25 × 1 mark
- Question 6 of 35
Why do we need exercise?
- Question 7 of 35
Which of these plants has a fibrous root?
- Question 8 of 35
Which of these planets is closest to the Sun?
- Question 9 of 35
Which kind of house is a wooden house that floats on water?
- Question 10 of 35
Sublimation changes what?
- Question 11 of 35
In burning coal, chemical energy changes into ______.
- Question 12 of 35
How are the seeds of a lotus carried away?
- Question 13 of 35
In a food chain, which of these is a herbivore?
- Question 14 of 35
Which of these animals lays eggs?
- Question 15 of 35
How long does it take for the Moon to go once round the Earth?
- Question 16 of 35
What is the job of the part of the plant shown by the arrow?
- Question 17 of 35
Which part of the mouth is used for making food wet and soft so that it is easy to swallow?
- Question 18 of 35
What does the skull do?
- Question 19 of 35
Which of these does NOT dissolve in water?
- Question 20 of 35
How many incisors does a grown-up have?
- Question 21 of 35
A lack of which of these causes scurvy?
- Question 22 of 35
Which living thing is missing from this food chain? (Each arrow means is eaten by.)
- Question 23 of 35
Which fibre do we get from sheep?
- Question 24 of 35
Which of these is a solid?
- Question 25 of 35
What is the best way to reduce soil pollution?
- Question 26 of 35
What is the best thing to wear for riding a scooter?
- Question 27 of 35
Which organ take oxygen from the air into the blood?
- Question 28 of 35
Which of these waste materials will rot away in the soil?
- Question 29 of 35
An eagle is ______.
- Question 30 of 35
Which planet is number 4 counting outwards from the Sun?
Section 3 — Achievers Section · 5 × 2 marks
- Question 31 of 35
Complete the analogy.
dodder : parasitic plant :: ______ : insectivorous plant
- Question 32 of 35
Read the statements about plants and animals and choose the correct option.
(i) The penguin gives birth to its young.
(ii) The lotus is suited to a muddy seashore swamp.
(iii) The woodpecker's beak is made for catching fish.
(iv) The cactus is suited to a hot, dry desert.
Which of these statements are true?
- Question 33 of 35
Complete the analogy.
weak bones : calcium :: ______ : Vitamin C
- Question 34 of 35
Read the statements about matter and force and choose the correct option.
(i) A ball rolling on grass slowing down and stopping happens because of gravity.
(ii) Sand dissolves in water.
(iii) A magnet pulling an iron pin towards it happens because of gravity.
(iv) Drops of water forming on the outside of a glass of cold water is an example of condensation.
Which of these statements are true?
- Question 35 of 35
Find the missing number, if the same rule is followed in every row.
12 11 4 6 4 8 11 3 ?
Answer key and explanations (opens below)
1. (D) 2. (B) 3. (B) 4. (D) 5. (B) 6. (A) 7. (A) 8. (B) 9. (D) 10. (A) 11. (A) 12. (C) 13. (B) 14. (B) 15. (C) 16. (A) 17. (C) 18. (D) 19. (B) 20. (D) 21. (B) 22. (D) 23. (A) 24. (C) 25. (D) 26. (A) 27. (A) 28. (A) 29. (B) 30. (C) 31. (B) 32. (B) 33. (A) 34. (A) 35. (C)
- 1. (D)
Counting 1 day back from Tuesday gives Monday.
- 2. (B)
In dictionary order they read Bride, Bridge, Brief, Bring, Brisk. The 2nd word is Bridge.
- 3. (B)
The rule is to take away 6 each time: 81, 75, 69, 63, 57, so the next number is 51.
- 4. (D)
33, 15, 24 are all in the table of 3, and 26 is not.
- 5. (B)
Each letter is 2 places after the one before it, so after W comes Y.
- 6. (A)
We need exercise because it keeps the muscles and the heart strong.
- 7. (A)
A wheat has a fibrous root — many thin roots of about the same size.
- 8. (B)
Counting outwards from the Sun, Mercury is number 1 — the closest of these four.
- 9. (D)
A houseboat is a wooden house that floats on water.
- 10. (A)
Sublimation changes a solid straight into a gas — for example, camphor slowly disappearing when left open.
- 11. (A)
In burning coal, chemical energy becomes heat energy.
- 12. (C)
The seeds of a lotus are dispersed by water.
- 13. (B)
The deer is a herbivore — it eats only plants.
- 14. (B)
The crow lays eggs. The others give birth to babies and feed them milk.
- 15. (C)
It takes about 27 days for the Moon to go once round the Earth.
- 16. (A)
The arrow points at the leaf. The leaf makes food for the plant using sunlight.
- 17. (C)
The saliva is used for making food wet and soft so that it is easy to swallow.
- 18. (D)
The skull protects the brain.
- 19. (B)
Chalk powder does not dissolve, however long you stir. The others dissolve and seem to disappear.
- 20. (D)
The answer is 8. A young child has 20 milk teeth. A grown-up has 32 — 8 incisors, 4 canines, 8 premolars and 12 molars.
- 21. (B)
scurvy is caused by too little Vitamin C, which we get from oranges.
- 22. (D)
The chain reads grass → rabbit → fox. The rabbit is a herbivore — it eats only plants.
- 23. (A)
Wool comes from sheep.
- 24. (C)
A solid keeps its own shape and its own size.
- 25. (D)
Soil pollution comes from radioactive waste and too much fertiliser dumped on land, so the fix is using compost instead of chemical fertiliser.
- 26. (A)
A helmet, because it protects the head in a fall.
- 27. (A)
The lungs take oxygen from the air into the blood.
- 28. (A)
Things that were once alive — peel, paper, cotton, leaves — are broken down by tiny living things in the soil.
- 29. (B)
An eagle is a carnivore — it eats other animals.
- 30. (C)
Mars is planet number 4 from the Sun — the red planet, named for the colour of its dust.
- 31. (B)
A dodder is parasitic and a pitcher plant is insectivorous.
- 32. (B)
(i) is wrong: The penguin lays eggs. (ii) is wrong: The lotus is suited to a pond. (iii) is wrong: The woodpecker's beak is made for drilling into tree bark for insects.
- 33. (A)
weak bones comes from too little calcium, and scurvy from too little Vitamin C.
- 34. (A)
(i) is wrong: A ball rolling on grass slowing down and stopping happens because of friction. (ii) is wrong: Sand does not dissolve in water. (iii) is wrong: A magnet pulling an iron pin towards it happens because of magnetic force.
- 35. (C)
In each row, (first − second) × 4 = third, so (11 − 3) × 4 = 32.
About this mock test
- Is this ISO Class 4 mock test really free, with no login?
- Yes. The whole paper is on this page: no account, no sign-up, no phone number and no ads. Nothing your child answers here is sent anywhere or stored.
- How is it marked?
- The same way as the SOF paper: Logical Reasoning 1 mark a question, Science 1 mark a question, Achievers Section 2 marks a question, 40 marks in all. Press Finish and mark to see the score by section and the right answer, with an explanation, under every question.
- Can I print it?
- Yes. Print paper + OMR sheet lays it out like the real paper, with a bubble sheet and the answer key on its own last page so it can be set aside. Choose Save as PDF in the print dialog to keep a copy.
- Is it the same as the real ISO paper?
- It has the real paper's shape — 35 questions, the same sections in the same order, the same marks and the same 60 minutes — and its questions come from the ISO Class 4 syllabus. The questions are Sprinto's own, not SOF's; Sprinto is not affiliated with the Science Olympiad Foundation.
Fresh questions every time
This paper stays the same so it can be printed and shared. In the app every ISO Class 4 question is new, the next one is picked to be just hard enough, and mistakes come back until they stick. Still free.