Donnell Koh graduated from the National University of Singapore with an Honours in Chemical Engineering. After receiving his Postgraduate Diploma in Education from the National Institute of Education (NIE), Singapore, he taught in junior colleges, working closely with students from a wide spectrum of backgrounds – the extremely weak to the highly gifted. He knows what works for students and what does not. His lessons focus on getting students to understand the basics and helping them to make connections among the different Chemistry topics. Donnell is the founder and principal Chemistry tutor of Twig Learning Center. With his vast experience, he has designed a set of powerful learning strategies and techniques that he has been using to teach his students to help them achieve excellent results in an incredibly short period of time.