I teach Maths and Chemistry through practicing solving questions and problems. I always ask students what topics they want to focus on but I also try to spot what the students need more practice with by going over the past exam papers. I believe that working through questions is more beneficial to the student than just providing them with theory on the topic, since that what the school focuses on. As a tutor I make sure the students have a great understanding of the principles of each topic but also that they get good practice and feel comfortable in that topic.