How Science Works 18 June, 2018 Changing Variables

Changing Variables Learning outcomes: 18 June, 2018 Changing Variables Learning outcomes: By the end of the lesson you should be able to; Identify the variables in an experiment. Carry out an experiment to investigate the effect of changing the different variables.

Changing Variables Recap: Independent Variable Dependent Variable 18 June, 2018 Changing Variables Recap: Independent Variable Something that is changed by the scientist. Dependent Variable Something that might be affected by the change in the independent variable Controlled Variable A variable that is not changed Starter for lesson: Give a recap of what they did in last lesson – the PowerPoint ‘how science works – variables’. Test pupils to see if they remember what the different kinds of variable are. Approximately 5 minutes.

Changing Variables TASK 1: ‘Dissolving Sugar’ 18 June, 2018 Changing Variables TASK 1: ‘Dissolving Sugar’ Complete the ‘dissolving sugar planning sheet’ you have been given, trying to think of as many different variables as you can for this experiment. Give pairs approximately 15 minutes to complete the planning sheet.

Changing Variables Solvent type Solvent amount Temperature Sugar 18 June, 2018 Changing Variables Solvent type Tap water, distilled water, salt water, vinegar, alcohol, propanone etc. Solvent amount Large, medium, small etc. Temperature Cold, warm, hot etc. Sugar Cubes, brown, caster, icing, granulated, fructose, crystals etc. Stirring Direction, speed, duration etc. Get student to define solvent. Approximately 10 minutes to go through variables. Take feed back from the class on any that they have thought of that are not on the list.

Changing Variables TASK 2: Practical 18 June, 2018 Changing Variables TASK 2: Practical Divide yourself in to pairs or threes. Decide on your independent variable - temperature of water, amount of water or type of sugar. Collect an instruction sheet and READ CAREFULLY. Main activity: Approximately 30 minutes + clear up time. Groups who work well can complete more than one experiment. Higher ability classes may not need the worksheets, they may be able to use their individual planning sheets.

Changing Variables SAFETY FOR PRACTICAL CAUTION hot water 18 June, 2018 Changing Variables SAFETY FOR PRACTICAL CAUTION hot water Do not walk around with hot beakers. Remain standing while carrying out practical.

Changing Variables TASK 3: Writing up your results. 18 June, 2018 Changing Variables TASK 3: Writing up your results. Use the ‘dissolving sugar results sheet’ to help you write up your results. Don’t forget to draw your graph on graph paper and attach it to the sheet. Give each student a copy of the results sheet (alternatively have it photocopied on to the back of the planning sheet) and allow them approximately 15 minutes to complete it, including the graph.

Changing Variables Plenary: Class discussion of results 18 June, 2018 Changing Variables Plenary: Class discussion of results What did you find out? What did the other groups find out? KEY QUESTION: Why is it important to have controlled variables? Allow approximately 5 - 10 minutes discussion of class results. Give students approximately 5 – 10 minutes to write a paragraph to answer the key question.