Cambridge Primary Checkpoint 0846 · Topic 1 of 10

Thinking and working scientifically

Planning fair tests, choosing variables, making predictions, recording results in tables and graphs, and drawing conclusions.

📌 Key points

Scientists ask questions and plan investigations to answer them.
In a fair test you change only one variable and keep all the other variables the same.
The variable you change is the independent variable. The variable you measure is the dependent variable. The ones you keep the same are control variables.
A prediction says what you think will happen and why, e.g. "A bigger parachute will fall more slowly because it has more air resistance."
Repeat measurements and find the mean to make results more reliable. A result that does not fit the pattern is called anomalous.
Record results in a table with clear headings and units, e.g. "Time (s)".
Use a bar chart when the thing you change is in groups (e.g. types of material). Use a line graph when both variables are numbers (e.g. time and temperature).
A conclusion says what the results show, e.g. "The warmer the water, the faster the sugar dissolved."
Other types of enquiry include observing over time, looking for patterns, identifying and classifying, and research using books or websites.

Variable: Something that can change in an investigation, such as temperature or time.
Fair test: An investigation where only one variable is changed and the others are kept the same.
Independent variable: The variable you choose to change.
Dependent variable: The variable you measure or observe.
Control variables: The variables you keep the same so that the test is fair.
Prediction: What you think will happen in an investigation, with a reason.
Anomalous result: A result that does not fit the pattern of the other results.
Conclusion: A statement that explains what the results show.

Mia wants to find out if the temperature of water changes how fast sugar dissolves. How should she plan a fair test?

Independent variable (what she changes): the temperature of the water, e.g. 20 °C, 40 °C and 60 °C.
Dependent variable (what she measures): the time the sugar takes to dissolve, using a stopwatch.
Control variables (kept the same): the amount of water, the amount and type of sugar, and how she stirs.
She should repeat each test and work out the mean time.
Answer: change only the temperature, measure the time, and keep everything else the same.

💡 Test tip

In a fair test question, find the one thing that is being changed. Everything else must be kept the same.

Test yourself8 questions from a bank of 22. A new mix every time.