- Ng, O. (2021, April-May). Transformative technologies or transformative pedagogies? Workshops on using technologies for conceptual mathematics teaching and learning. Invited workshop series for Hong Kong Association of Mathematics Education.
- Ng, O. (2021, January). Research and trends in mathematics teachers’ professional development. Invited presentation at Annual General Meeting of Hong Kong Association of Mathematics Education.
- Ng, O. (2021, January). Using videos to support STEM teachers’ professional development regarding technology integration. Invited presentation at PALMS Virtual Symposium 2021.
- Ng, O. (2020, September). Catering to learning diversity in the mathematics classroom. Invited presentation at Fung Kai Liu Yun Sum Memorial School on Professional Development Day.
- Ng, O. (2019, October). Learning as Making: Using 3D technologies to support the teaching and learning of secondary school mathematics. Invited presentation at David Li Kwok Po College.
- Ng, O. (2019, August). Implementing a ‘Learning as Making’ pedagogy in school mathematics. Invited presentation at Fung Kai Liu Yun Sum Memorial School on Professional Development Day.
- Ng, O. (2018, June). Supporting visualization in STEM: 3D printing. Invited presentation at the Mini-symposium on TEAL in Tertiary STEM Education, Hong Kong Polytechnic University, Hong Kong.
- Ng, O. (2017, June). Using emergent technologies to enhance the learning and teaching of STEM in Hong Kong’s secondary schools. Invited seminar presented at the Chinese University of Hong Kong, Hong Kong.
- Ng, O. (2017, February). From classroom teaching to classroom researching: Reflections, sharing and perspectives from a teacher-researcher. Invited research seminar presented at the Simon Fraser University, Burnaby, BC, Canada.
- Ng, O. (2016, June). “3D pens” and 3D printing: Research, ideas and discussion. Invited seminar presented at the Imperial Oil Science Technology Engineering and Mathematics (IOSTEM) 2016 Research Symposium, Vancouver, BC, Canada.
- Ng, O. (2016, January). Language, gestures and touchscreen-dragging in school calculus: Bilinguals’ linguistic and non-linguistic communication. Invited research seminar presented at the Chinese University of Hong Kong, Hong Kong.
- Ng, O. (2015, October). Doing MUCH more with your tablet PC, iPads, Androids, and student-owned technology. Presentation at the 54th Annual Northwest Mathematics Conference, Whistler, BC, Canada.
- Ng, O. (2014, October). FTC: Explained! Teaching pre-calculus and calculus visually, conceptually, and dynamically. Presentation at the Annual Conference of the British Columbia Association of Mathematics Teacher, Guilford Park Secondary, Surrey, BC, Canada.
- Ng, O. (2013, October). Introduction to dynamic mathematics environment: Designing applets and lessons that foster dynamic thinking and multiple representations in pre-calculus and calculus. Presentation at the Annual Conference of the British Columbia Association of Mathematics Teacher, Steveston London Secondary, Richmond, BC, Canada.