Take the numbers 1, 2, 3, 4, 5, 6 and choose one to wipe out.
For example, you might wipe out 5, leaving you with 1, 2, 3, 4, 6.
The mean of what is left is 3.2.
1. Can you figure out how to wipe out just one number from 1 to 6, and leave behind a mean which is a whole number? Is there more than one solution?