He was soon back at Nan Chiau High School, this time as an adjunct teacher to Sec 4 students as well as mathematics coach to the school's Olympiad contestants.

Different paths to a solution

"I like to think about questions and come up with my own methods," shares Mr Ho of his approach to the subject. In his book, there's more than just one way to solve a problem. Maths formulae and concepts may have remained unchanged over the years, but Mr Ho sees a vast difference in every batch of students. "Students in the 1970s were not the same as those today," he explains. "They come with a different base of knowledge and family backgrounds."

Maths is a fun and living subject for students in Mr Ho's classes.

Refusing to lump together all students who are poor in maths, Mr Ho believes it is necessary to identify the cause of their poor performance before taking remedial action. "There are many reasons why some students are not good at maths," he says.

"Some are slower learners. Others are lazy and do not practise. Still others are actually good but careless in their work. Some students also have 'blind spots', being very good in certain topics but poor in others. There are also students who have problems at home. You must understand what the student needs before you can help him or her."

Making maths come alive

How does Mr Ho deal with students who find maths meaningless with respect to real life?

"To get a student to like maths is not easy," states Mr Ho. "First, you yourself must be very good in maths." Having a big bag of tricks is vital, as "using the same approach in class for all students doesn't work," he stresses. "The teacher must know how to present maths in different ways and angles."

In his classes, Mr Ho frequently uses examples from real life to make maths interesting. For instance, he points out how the concept of integration allows one to determine the area covered by an irregular plot of land and thus its market value. Probability theory becomes a tool to understand how lotteries and casinos work. "The students then want to know how they can increase their probability of winning!" laughs Mr Ho.

Maths is a passion that keeps Mr Ho teaching even after retirement.

And should you get yourself nabbed by the traffic police for alleged speeding, Mr Ho suggests you divide your distance travelled by the time you took to convince the cop that your average speed was way below the limit. It might not save you from a ticket, but you'll never forget how to use the formula either.

Mr Ho also challenges promising students to develop their problem-solving skills. "I give them questions that are slightly above their level, that are not from the textbooks but from my own methods," he reveals. His competency in maths is widely acknowledged, both by the younger teachers he mentors at Nan Chiau High School, as well as fellow mathematicians. In fact, he was recently invited to be a reviewer for Mathematical Reviews, a research journal by the American Mathematical Society.

The effectiveness of Mr Ho's methods is clear in Nan Chiau High School's maths performance. Last year, nearly 90 per cent of the school's 'O' level students obtained a distinction in Mathematics, and many of its students have taken part and won awards at the Singapore Mathematical Olympiad.

"Everyone can be a mathematician," declares Mr Ho, who has no regrets in giving up his time for calligraphy and reading to spend a few hours in school each day. And even though many of his students go on to be teachers, doctors, engineers and chemists, they'll heartily agree with him whenever they return to school to thank him. He was, after all, the teacher who taught them the principles they live by and use everyday.