More students who require academic help are turning to online tuition. More than 15 tuition centres and private tutors have started offering such classes in recent years, in addition to traditional face-to- face ones.
Tutors and parents told The Straits Times they are more convenient than face-to-face sessions.
Online tuition relies on video chat applications such as Skype and Google Hangouts to communicate, and file-sharing tools like Dropbox to assign worksheets.
Paya Lebar Methodist Girls' School (Secondary) student Berdine Yeo, 14, signed up for a $200- a-year weekly online maths tuition programme two years ago to prepare for her Primary School Leaving Examination (PSLE).
She used the online service offered by PSLEMath Learning Centre to supplement her face-to-face tuition. Her father, manager Yeo See Kiat, 48, said: "It provided her with the extra help needed and also more practice in the subject."
IB Super Tuition Centre, which offers face-to-face tuition for a number of subjects, including International Baccalaureate (IB) maths and science, introduced its online service a year ago. The number of students using the online option has risen five times from last year.
The centre now has 15 students on this online arrangement, compared with only three last year.
For at least one session a week, students clarify their doubts, go over key concepts and attempt questions using online tuition software fitted with video conferencing, an online whiteboard and file-sharing capabilities.
There is no price difference between face-to-face classes and online classes, which cost $100 to $130 per 90-minute session.
Centre founder Bel Hwang said students can now receive help with their homework any time, and in the comfort of their home. "Students these days are more comfortable with technology," she said. "Parents do not have to worry about their children travelling to a centre. Some parents also prefer online tutors to home tutors as they dislike having strangers go to their house."
Tamilcube Learning Centre, which has three physical centres, started its online Tamil tuition this year. Study materials are placed online in advance. Students then log on to Skype at a scheduled time for weekly classes, which each lasts about 90 minutes.
Students pay $55 per class, similar to fees at tuition centres.
Tamilcube director Alagupillai Thiruvupillai, 48, said: "With online tuition, tutors can teach hundreds of students without a need for large classrooms."
However, just 5 per cent of his 120 students learn online.
Numberskill Math Tuition Centre, which offers O-level, A-level and IB tuition, introduced its online service this year.
Its principal tutor, Mr Gary Ang, 36, said: "Parents want their children to attend classes by proven tutors, and if the schedule doesn't allow for it, they see online tuition as the next best option."
However, SmartLab Education Centre, an early provider of online classes, has discontinued its online programme since 2012. Co-founder Tony Tan, 45, said that there are limitations to online tuition and it is "not as personal" as being there in a class. "It takes a lot of time trying to communicate with the students, who may not be able to express themselves as well through an online platform," he said.
"After a session, the tutors too are tired, not so much from the content that needs to be taught but from ensuring students receive whatever they are trying to impart." He added that it is easier for tutors to point out mistakes and explain solutions at face-to-face sessions.
National Institute of Education professor Jason Tan noted that while some students can learn independently, others need a tutor next to them. He added: "Some children need that supervision to keep them focused on the task so they do not do something else instead."