Year 7 Science · Unit 4 · Lesson 6
Foundation Worksheet
Learning Goals
Match each word to its meaning
Write the letter of the matching meaning in the middle column. Each letter is used once. The meanings are not in the same order as the words.
| Word | Letter | Meaning |
|---|---|---|
| Independent variable | A. A sentence that answers the question, using the data as evidence | |
| Dependent variable | B. Measuring the same thing again and again at regular times | |
| Controlled variable | C. The general direction of the data, such as increasing or decreasing | |
| Series of observations | D. What you measure to see the result of the change | |
| Trend | E. The one thing you change on purpose | |
| Conclusion | F. Anything you keep the same so the test is fair |
Sort the variables: the fizzy tablet test
A class asks: does the temperature of the water affect how long a fizzy vitamin tablet takes to stop fizzing? Write each item in the correct box. The boxes do not hold the same number of items.
Independent (change)
Dependent (measure)
Controlled (keep the same)
Plot the graph: a dripping tap
Scenario
A leaking tap drips into a straight-sided container. Every 5 minutes, a student measures the depth of the water with a ruler.
| Time (min) | 0 | 5 | 10 | 15 | 20 |
|---|---|---|---|---|---|
| Depth of water (cm) | 0 | 1.5 | 3.0 | 4.5 | 6.0 |
Source: sample class results.
1. Which variable is the independent variable, and which is the dependent variable? Which one goes along the bottom (horizontal) axis?
2. Plot the results from Table 1 on the grid. Label each axis with its name and unit, then draw a trend line.
3. Describe the trend. Then use your line to predict the depth after 25 minutes.
Is it a fair test? Jack’s paper planes
Scenario
Jack wants to know if paper planes with bigger wings fly further. He throws a big-winged plane on the oval on a windy afternoon. The next morning he throws a small-winged plane in the school hall, where there is no wind. The small plane flies further, so Jack says small wings are better.
4. Jack meant to change only the wing size. Name two other things that also changed between his two throws.
5. Explain why Jack cannot trust his conclusion.
6. Redesign Jack’s paper plane test so that it is fair. Say what he should change, what he should measure (with a unit), and two things he must keep the same. Say how he should record his results, and why his new result could be trusted.
Match each word to its meaning
Independent variable → E; Dependent variable → D; Controlled variable → F; Series of observations → B; Trend → C; Conclusion → A. 1 mark per two correct. [3 marks]
Sort the variables: the fizzy tablet test
Independent: the temperature of the water. Dependent: the time until the fizzing stops. Controlled: the volume of water; the brand and size of the tablet; the type of cup; not stirring. All 6 = 3; 4 or 5 = 2; 2 or 3 = 1. [3 marks]
Plot the graph: a dripping tap
1. Independent: time; dependent: depth of water (1). Time goes along the bottom axis (1). [2 marks]
2. Axes labelled “Time (min)” across and “Depth of water (cm)” up (1); five points plotted correctly (1); a straight trend line through them (1). [3 marks]
3. Increasing: as time increases, the depth increases steadily, 1.5 cm every 5 minutes (1). About 7.5 cm at 25 minutes (1). [2 marks]
Is it a fair test? Jack’s paper planes
4. Any two, 1 each: the place (oval or hall); the wind (windy or still); the day and time. [2 marks]
5. More than one thing changed, so he cannot tell whether the wing size or the wind caused the difference (1). A fair test changes only the independent variable (1). [2 marks]
Question 6
Marking guide: 1 independent: wing size; 1 dependent: distance flown, in metres, measured with a tape measure; 1 two controlled variables (same place with no wind, same paper, same thrower and throwing height); 1 a results table with wing size and distance (m) as headings, repeating each throw; 1 only wing size changes, so it must have caused any difference. [5 marks]
Model answer: Jack should change only the wing size and measure how far each plane flies, in metres, with a tape measure. He should throw both planes in the hall on the same day, with the same paper and the same throw. He should record each wing size and distance (m) in a table and repeat each throw. Because only the wing size changes, it must have caused any difference in distance.
Common error: swapping the variables. The independent variable is the one you choose to change; the dependent one is what you measure.