When I was a high school sophomore, I wrote notes to get out of taking tests one semester, and it was an awful semester. I was constantly behind and making up the work was a huge challenge. I really hope your student makes these up quickly. It's hard to have things pile up, especially in a subject like math. I'm not sure what I would do if a student took a test with them. I don't know if I would allow for them to take a make-up because they would have an advantage by already seeing the test questions. The makeup would have different numbers, but the questions would be the same. (I understand that this isn't much of an issue for you because you tell your students exactly what will be on the test, but I don't do that.) Also, I require students to make up tests and quizzes within a week if they are sick or it gets entered in as a zero. I haven't had to give anyone a zero yet, but I have had to constantly remind students to come to take makeups. Of course, if a student has an issue or a lot of other work to make up, I have no problem with them making it up later if they just let me know. In college, if you miss an exam (which shouldn't happen unless you are extremely sick), most professors had you make it up right a way.