• Quick retrieval from earlier learning (Independent, dependent and control variables; Reading tables and line graphs). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Investigation: How does the mass of a pendulum bob affect the time of one swing? Which is the independent variable (the one you change)? (minutes of exercise / mass of the bob / length of the string / time for one swing) → mass of the bobPrompt: Independent variable: the one you change. Dependent variable: the one you measure.
2. Investigation: Does the number of cells (batteries) affect how bright a bulb is? Which is the dependent variable (the one you measure)? (length of wire / time for the water to evaporate / brightness of the bulb / number of cells) → brightness of the bulbPrompt: Independent variable: the one you change. Dependent variable: the one you measure.
3. Investigation: Does the temperature of water affect how quickly sugar dissolves? Which is the independent variable (the one you change)? (water temperature / mass of the bob / volume of water / time for the sugar to dissolve) → water temperaturePrompt: Independent variable: the one you change. Dependent variable: the one you measure.

• Show a simple experiment with one thing changed and ask what makes it a fair test.
• Share the objective: Drawing conclusions from evidence. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: A result does not match the prediction. What should a scientist do?
• Step 1: Unexpected results are kept and investigated; sometimes the prediction was wrong.
• Step 2: So the answer is: Record it and check whether the method was correct
• Answer: Record it and check whether the method was correct
• Pause after each step and ask a student to say what comes next.

• Do these together. Students try each step on whiteboards before you reveal it.
• Use the hints as prompts rather than giving the answer.

1. Which conclusion goes too far? Results: cress grew taller with more light, from 0 to 8 hours a day. (Cress will keep growing taller with any amount of light, even 24 hours. / Between 0 and 8 hours, more light gave taller cress. / Light affected how tall the cress grew. / Cress with no light grew least.) → Cress will keep growing taller with any amount of light, even 24 hours.Prompt: The test only went up to 8 hours.
2. Conclusions: which statement is true? (If two things happen together, one must cause the other. / A conclusion can include amounts you did not test. / One result is enough to prove a theory. / A larger sample gives more trustworthy results.) → A larger sample gives more trustworthy results.Prompt: Think about what results can and cannot show.

• Students work on the student sheet. Circulate and check the first two answers of every student early.
• Students who finish: write a question of their own for a partner, with the answer.

The 6 questions are on the student sheet below, with answers in the key.

• Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.

1. Conclusions: which statement is NOT true? (If two things happen together, one must cause the other. / Repeating an investigation makes results more reliable. / Two variables can be linked (correlated) without one causing the other. / A larger sample gives more trustworthy results.) → If two things happen together, one must cause the other.Prompt: One statement is a common mistake about evidence.
2. A result does not match the prediction. What should a scientist do? (Record it and check whether the method was correct / Change the result to match / Delete the result / Stop doing science) → Record it and check whether the method was correctPrompt: Evidence is more important than the prediction.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-6.