Primary 4 · Science · Process Skills: Fair Test & Variables
Process Skills: Fair Test & Variables questions for Primary 4 Science
10 questions to work through online, 2 of them written out the way the paper asks. Answer and you get the working straight away, then a score at the end. No sign-up, and you can retake it as often as you like.
- Choosing the right pair
- What the third set-up is for
- Naming the variables
- Spotting the flaw
- Conclusion from results
- Repeating and averaging
- Going beyond the results
- Naming what is kept the same
- Naming the aim
- Designing the comparison
Same picture as the question above.
| Cloth | Time to dry in the shade (min) | Time to dry in the sun (min) |
|---|---|---|
| A | 95 | 40 |
| B | 88 | 37 |
| C | 102 | 44 |
Answers and explanations for all 10 questions
Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.
Which two set-ups shown above should be compared to find out whether the amount of water affects how much a plant grows?
Answer: P and Q
To test water, the two set-ups must differ only in water. P and Q are both in sunlight and differ only in how much water they get.
Using the same set-ups, what could set-up R be compared with to test whether light affects growth?
Answer: set-up P
P and R both get 50 ml of water and differ only in light, so that pair tests light. One set-up can serve in two different comparisons.
A pupil rolls the same ball down ramps of different heights and measures how far it rolls. Which two statements are correct?
Answer: A and B only
The pupil decides the ramp height, so that is what is changed. The distance is what comes out of the experiment, so that is what is measured.
To test which paper towel absorbs more water, Devi dipped a large sheet of towel A and a small sheet of towel B into water. Why can she not trust her result?
Answer: The two sheets were not the same size.
A bigger sheet takes up more water simply because it is bigger. To compare the towels themselves, the sheets must be the same size.
Based on the table above, which conclusion is correct?
Answer: All three cloths dried faster in the sun than in the shade.
Every row shows a shorter time in the sun than in the shade — 40 against 95, 37 against 88, 44 against 102. That is all the table lets you conclude.
A class measured the same thing five times and got 21, 22, 21, 43 and 22 seconds. Which two statements are sensible?
Answer: A and B only
Four readings cluster near 21-22 and one is double. Repeating is what made that visible, and the odd one out is the one to check.
A pupil tested three brands of battery in one torch and found brand X lasted longest. Which conclusion goes too far?
Answer: Brand X batteries last longest in every device.
One torch was tested, so nothing can be said about every device. A conclusion may only cover what was actually tested.
In the ramp experiment, the pupil uses the same ball every time so that the ball itself cannot affect the result. Things kept the same like this are called ______ variables. (One word.)
Answer: constant
Variables held still so they cannot affect the result are the constant variables.
Two set-ups are identical except that one is wrapped in foil and one is not, and the temperature of each is measured. What is being tested — whether the ______ affects how fast the water cools?
Answer: foil
The one difference between the set-ups is the foil, so that is what is being tested.
A pupil wants to know whether a lid keeps a drink hot for longer. What should the second set-up be?
Answer: the same cup with the same drink at the same temperature, without a lid
The two set-ups must be identical except for the one thing being tested. Everything stays the same and only the lid is removed.