I am in my second year with East Helena School District and this year I have taken on the roll as the TOSA at the Middle and High Schools. If you're asking what TOSA is, you're not the only one. TOSA stands for Teacher on Special Assignment. I help out wherever I can. One day I could be helping in a 6th grade science class and the next may be high school social studies. This year I will also be helping all the online students navigate their way through their courses.