And I thought I was being so careful!

For summer school we have been pre-assessing the students to see where they are so that we can determine what areas they need help in so that they can catch up during summer school.  I had been carefully printing the logins and passwords as they were case sensitive.  I was also being very careful to list the zero's with a slash through them to differentiate them from the letter "O".  In class, I had handed out the sheet with logins and passwords, and was having the students login to take their assessment.  I help with the technology stuff because Ms. Herrell doesn't feel as comfortable with the technology.  This one kid seemed to be having problems, so I quietly asked what was wrong, and he said something like "Miss Markus, I can't find this key anywhere!" and pointed at the zero.  It had never occurred to me that they wouldn't know something like that, so I told him that was how we differentiated zeros from the letter O, and then his login worked just fine.