No problem worth solving is solved in one day/period. We need real problems that take genuine thought to develop patient problem solvers. Give a visual and ask a question, let the conversation commence. Introduce mathematical notation and symbols, then add measurements, bring in the math at the end.
Spend more time on the formulation of the problem than anything else. How the question is asked is more important than giving a nice clear problem solving process. -Dan Meyer, TED talk