Variables: Variables are things in a model that can change. On your blog list as many variables from the lemonade model as you can eg the 'weather' is a variable as this changes.
Rules: Rules in a model describe what will happen if a variable (or different combinations of variables) change. On your blog list as many rules from the lemonade model as you can eg 'if the price is too high you sell less lemonade' is a rule as it describes what will happen if the price variable is too high.
Answer the questions on the teachers presentation.