As Singapore's knack for topping the charts of global mathematics and science tests gains fame, its teacher training methods have also drawn interest overseas.
The National Institute of Education (NIE) International - the business consultancy arm of NIE - has been training more educators worldwide in leadership skills, curriculum planning and teaching methods.
What was once a "very small unit within one of NIE's programme offices" has become a main way the teacher training institute shares its expertise abroad, said Professor Lee Sing Kong, its managing director.
The consultancy, which started in 2003, took in revenue of $5 million to $6 million annually in the past three years, he noted.
In its early years, it raked in an average of $3 million to $4 million, he said, adding that the earnings fluctuate yearly depending on the size of projects.
The first request came from Abu Dhabi more than 10 years ago to review the quality of its teachers, and train them. One of the consultancy's recommendations was for a teacher training college, which it later helped to set up.
Since then, it has trained about 7,000 educators from about 35 countries in areas such as teaching and assessment method, and school management.
Its flagship programme, which was launched in 2006, is the Leaders-in-Education Programme International, a two-week course in which participants gather at the NIE to network and brainstorm on changes in education and school leadership. They also visit schools here to learn about the system.
The programme has trained 363 educators so far.
Dr Goh Chor Boon, NIE International's general manager, said most participants are teachers, principals and ministry officials.
Its programmes, which range from three-day visits to three-month courses, are customised to the needs of countries.
For instance, in one of its latest projects - in Jamaica in July - 80 university maths teachers attended a customised one-week course to learn to use real world statistics such as airport passenger arrivals or car population numbers in a city.
Prof Lee said there are lessons Singapore has learnt that it can share, even though education systems cannot be tele-ported in total as there are local and cultural factors to consider.
He added that the consultancy only responds to requests, and it does not bid actively for business.