The Ratio Machine produces accurate results, if the measurements are made carefully. Since all students are doing the same thing with the same equipment, it is expected that their results will be the same. When the results are not the same, the question is: "Why are the results different?" Explore the differences with the class, using questions such as:How can you explain the different numbers? What might have happened?Which of the results do you think are the more accurate? Why do you think so?section at the end of the lesson provides possibilities for why some of the results are different.