Plan a fair experiment
Grade 6 Science Worksheet

Circle the best answer.
What is changed, towel brand; groups, A: 5 s, B: 30 s. In Esme's towel test, towel A is dipped in water for 5 seconds and towel B for 30 seconds. What should be fixed?
- Nothing; the dipping time does not matter
- Dip both for 30 s, but in different amounts of water
- Dip each towel for the same time
- Add two more brands to the test
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Use this
A book-stack ramp with three different balls beside it. Investigation card: what is changed, ramp height; what is measured, distance rolled; problem, different ball each time.
Jun rolls a ball down ramps of different heights and measures how far it rolls, using a different ball each time. What should change?
- Use the same ball for every ramp height
- Use a brand-new ball for every trial
- Change the floor too, for more variety
- Use one ramp height for every trial
Flights (model data)
Trial 1 Trial 2 Trial 3 Average 5.2 m 4.8 m 5.0 m ? Kira's paper airplane flew 5.2 m, 4.8 m and 5.0 m in three trials. What is the average distance?
- 5.2 m, the longest flight
- 15.0 m
- 4.8 m
- 5.0 m
Table, Trials, with columns Trial 1, Trial 2, Trial 3, Average. Why does Luz run three trials instead of one?
- Three trials make the hypothesis come true
- One trial could be off; an average is more reliable
- More trials give the scientist more things to change
- One trial is enough if it is done carefully
Groups, light: 1 plant, dark: 1 plant. Milo's plan tests one bean plant in light and one in a dark cupboard. What would make the results more reliable?
- Add a third plant in different soil
- Use one plant, but measure it twice
- Skip the plant in the dark cupboard
- Use several plants in each group
Four question cards. Which question could Noah answer with a fair experiment?
- Does the amount of salt change how fast ice melts?
- Is ice prettier than snow?
- Is salty ice more interesting to look at than plain ice?
- Which season is the nicest one?
"Do plants like music?" with an arrow to a blank card. Ren asks, "Do plants like music?" Which version can be tested?
- Is music good for people?
- Does music change how plants feel?
- Do plants enjoy songs?
- Does 1 hour of music a day change plant height in 3 weeks?
Note: average of 3 trials. Salted ice cubes melted in 12 minutes on average; plain cubes took 25 minutes. Which conclusion fits Tala's data?
- Salt will melt ice on any road in winter
- Salt made the ice cubes melt more slowly in this test
- In this test, salt made the ice melt faster
- Salt makes everything melt faster
Note: average of 3 trials. Which conclusion fits Zee's paper-towel results?
- Towels A and B soaked up the same amount
- Towel B will be the strongest and cheapest too
- Towel B soaked up the most water in this test
- Towel C soaked up the most water of the three towels
Note: 5 plants per group, after 2 weeks. Ari's hypothesis: if a plant gets more light, it will grow taller. Do the data support it?
- There is no way to tell without a control group
- Yes; the plants in light grew taller in this test
- No; the plants kept in the dark cupboard grew taller
- Yes, and light is the one thing plants need