As he copied the solution to the maths problem sum onto his worksheet, he realised that he was lost.
Primary school mathematics is tough.
But this was not a primary school pupil struggling with the question. He was a father of two in a course on primary school maths.
He was one of several parents going for "tuition" so they can better understand what their children have to deal with in school.
On Dec 6, Mohd Yusof Maruwi, who is in his early 60s, and his wife, Sanisah Ismail, 45, attended an eight-hour session on solving primary school maths problems. It was held at a multi-purpose room at Muhajirin Mosque.
Thirty parents attended the Parents Mastery workshop organised by Genius Young Mind, a centre which conducts maths tuition and workshops.
Mr Yusof, who is also a veteran actor and comedian, has an eight-year-old daughter and six-year-old son. The environment officer listened intently as the teacher explained the "branch" method to solve a fraction problem.
He has secondary education and last went to school 50 years ago. He said that now, he cannot even understand his own notes. "I looked at the question and thought, 'Alamak, so difficult.' Luckily, my wife could understand what was going on."
These parents are part of a growing trend of parents who attend classes so that they can help their children with their studies.
The latest Household Expenditure Survey found that families spent $1.1 billion a year on tuition. This is almost twice the $650 million spent a decade ago and a third more than the $820 million spent just five years ago.
There are 850 tuition centres and enrichment centres registered with the Education Ministry, up from 800 last year and about 700 in 2012.
The Parents Mastery workshop is conducted with the Students Math boot camp four times a year and costs about $700.
The parents were taught at least two methods of solving each mathematics problem.
After spending more than 15 minutes explaining a rather complex problem, the teacher said: "Your child has to answer a similar question in just a few minutes. So next time, don't be too hard on them if they can't solve a question."
Another tuition centre, Learning Out Of The Box, also runs regular workshops for parents. About 100 parents have joined the workshops so far.
Human resource executive Cindy Leow, 42, went for several workshops with her 12-year-old son, who sat his Primary School Leaving Examination last year.
The workshops dealt with solving mathematics problem sums and overcoming anxiety during examinations.