Chuen tries the mean of three numbers and announces that the method works in that case also. Mr. Hamilton asks the class to show it would always work. With some help, they argue that for any values x1, x2, and x3,
10.9x1 + 10.9x2 + 10.9x3 = 10.9(x1 + x2 + x3).
Shanika then observes, "It doesn't matter how many x's you have. You can always factor out the 10.9.