Ask students how someone could verify the accuracy of their purchases. Discuss why estimates vary in real-life situations. Have them discuss with each other their problem solving techniques. Discuss other ways this data could be presented. The presentation demonstrates clear thinking and explanation.
All work is complete and correct.
Task was accomplished in an exceptional manner. The students substantially achieved the mathematical and projected goals. The main idea and the mathematics behind the project is understood, there may be some minor misunderstandings in content, errors in computation, or weakness in presentation. The students partially achieved the mathematical and project goals. A limited grasp of the main ideas or project requirements is demonstrated.