The phrase describes a type of estimation or approximation, often sought when solving puzzles. It signifies a quick, imprecise method used to arrive at a solution without rigorous mathematical precision. An example would be determining an approximate cost for a project by considering only the major expenses, omitting minor details.
This approach offers the advantage of speed and simplicity. It allows for rapid assessment and decision-making when precise figures are unnecessary or unavailable. Historically, such methods have been crucial in situations requiring immediate action, such as battlefield assessments or preliminary budget planning.