This is amusing. I hope you realize that statisitcally, there is a VERY good chance your teacher smokes his or herself. Most of them can tell instantly if one of their students are stoned but most of them don't want to embarass them. Either thator they would rather humiliate them then get them in trouble with the administration. Face it, their making you go up to the board and doing complex math (revealing to the class how stoned you really are) is going to almost as effective as taking it up with the guidence counciler. Most teachers do not want their students to get into trouble but they do want them to care about their class as much as they do. So the next time you think, "man, I can't believe Mrs. Smokesalot didn't know I was on cough syrup or when I lit a joint in the back of class" they notice.