Help students reflect on what an experiment is. Begin a discussion on what it means to do an experiment:
Have the class brainstorm “What is a variable?” Then ask:
- What were you trying to find out about?
- What data did you collect?
- What did you change each time you took new data?
- In each experiment, what did you keep the same during the whole experiment?
- What did you change between experiments?
- Are there any variables in our Ratio Machine Experiments?
- Who can give one of the variables in the Ratio Machine Experiments?
Continue collecting examples of variables until students have identified the four variables. Emphasize that variables are things the students changed, or things that resulted from the changes they made