Primary 5 · Science · Process Skills: Fair Test & Variables
Process Skills: Fair Test & Variables questions for Primary 5 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.
- Predicting from a pattern
- Reading a graph
- What a result cannot show
- Identifying the flaw
- Choosing what to measure
- Judging reliability
- Explaining an odd result
- Naming the variable
- Designing from an aim
| Number of batteries | Brightness reading |
|---|---|
| 1 | 12 |
| 2 | 25 |
| 3 | 37 |
| 4 | 50 |
| Trial | Time for the ice to melt (min) |
|---|---|
| 1 | 14 |
| 2 | 15 |
| 3 | 38 |
| 4 | 14 |
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.
Based on the pattern in the table above, what reading would 5 batteries most likely give?
Answer: 62
The readings rise by roughly 12 to 13 each time: 12, 25, 37, 50. One more battery would give about 62.
Based on the graph above, which statement is correct?
Answer: Adding more fertiliser helps less and less as the amount increases.
The line climbs sharply at first and then flattens. Each extra amount of fertiliser adds less height than the one before.
A pupil found that plants near a window grew taller than plants in a cupboard. Which two statements are fair?
Answer: A and B only
The observation itself is fair, and light is a reasonable suggestion. But a window is warmer as well as brighter, so nothing here proves which of the two mattered.
A class compared two fertilisers by putting one on plants in the school garden and the other on plants in pots indoors. Why can they not compare the fertilisers?
Answer: The two groups differed in light, soil and temperature as well as in fertiliser.
Everything except the fertiliser should have matched. With the garden and the indoors differing in several ways, any difference could have come from any of them.
To find out which of two insulating materials keeps a drink warmer, what should be measured?
Answer: the temperature of each drink after the same length of time
The result is how much heat was kept in, and that shows up as the temperature after a fixed time. Everything else is either a constant or beside the point.
Which two of these would make an experiment's results more reliable?
Answer: A and B only
Repeating shows whether a result holds up, and one instrument removes differences between instruments. Changing two things and discarding awkward results both destroy the experiment.
Based on the table above, what is the most sensible thing to do about trial 3?
Answer: Check what was different about trial 3 and repeat it.
Three trials agree closely at 14 to 15 minutes and one is more than double. That points to something going wrong in trial 3, which is worth finding rather than averaging away.
A pupil tests how the length of a pendulum affects how long it takes to swing. The length is the ______ variable — the one thing changed on purpose. (One word.)
Answer: independent
The variable changed on purpose is the independent variable.
In the same pendulum experiment, the time taken for each swing is written down. That is the ______ variable — the one measured. (One word.)
Answer: dependent
The variable measured as a result is the dependent variable.
A pupil wants to know whether the colour of a container affects how fast water in it warms in the sun. What should differ between the containers?
Answer: only the colour of the containers
Only the thing being tested may differ. Same size, same water, same place — and then any difference in warming must be down to the colour.