I taught AP Chemistry, Regents Chemistry, Physics and Biology for over 30 years at a High School in Queens, New York. I have tutored high school and college level Chemistry, Physics and Biology for over 30 years, too. I emphasize mathematical methods, when applicable, estimation, and emphasis on units, using the factor labeling method of unit conversion. When I end a tutoring session, my main goal is to make sure my student has mastered and is comfortable with the material of the lesson. ...