One basket, several solutions
Plan a small shop that meets three conditions.
You have €10. Choose exactly three different products, including at least one fruit. You may choose one of each product. Several baskets work: find one and explain how you checked it.
What you will practise: Check every condition of a problem.
Think it through together
One person proposes a strategy; the other asks “why?” and looks for a case where it fails. Then swap roles. No names or speed competition needed.
Before viewing the explanation: what do we know, what are we assuming, and how would we check the result?