Dr David Treeby has taught mathematics for nearly 20 years and is Head of Maths Enrichment at one of Melbourne's leading boys' schools. He is the main author of Cambridge University Press's VCE Specialist Mathematics Units 1&2 and co-author of Units 3&4, as well as Enrichment Mathematics for Secondary Students. His doctoral research, "Further Thoughts on a Paradoxical Tower," earned the Mathematical Association of America's Merton M. Hasse Award.

Dr Treeby founded HD Maths to bring his enrichment approach to students outside the classroom, and designed the curriculum every class is built on. Teaching is delivered by a team of expect teachers who share that same standard — meet them below.