“Money Matters,” a play that opened last weekend in Cambridge, Mass., demonstrated the financial wit of its teenage actors at the same time that they – and the audience – embraced the complexities of money. Credit versus debt, income differences among classmates, money and relationships, certificates of deposit, needs versus wants – this only scratches the surface of the subject matter in the Youth Underground theater production, which begins touring the Boston area in February. The actors clearly were having fun, but their performance served as an educational tool that might be replicated. For example, the screenplay was based on the actors and other teenagers’ 80-some interviews of community residents about their financial viewpoints and mishaps. The stories generated ideas…