"A penny saved is a penny earned" means that little by little you will save money by not spending your money. Example: "I'm going to give you $20 but I want you to put it in the bank; a penny saved is a penny earned!" Not spending money has the same result as earning money, so to save a penny is the same as earning a penny. "A penny saved is a penny earned" compares saving money to earning money one penny at a time. Example: "My dad never lets me spend money on things I don't need. He always says a penny saved is a penny earned."