mathematics

Telephone numbers in Singapore

Telephone numbers in Singapore is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Telephone numbers in Singapore rather than just read about it. In short: Telephone numbers in Singapore, also known as the National Numbering Plan, are regulated by the Info-communications Media Development Authority (IMDA). Due to the small geographical size of Singapore, there are no area or trunk codes; all numbers belong to one numbering area, and thus come in the same 8-digit format.

Key takeaways

Telephone numbers in Singapore belongs to mathematics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Telephone numbers in Singapore to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Telephone numbers in Singapore from memory before moving on to harder problems.

Reference excerpt

Telephone numbers in Singapore, also known as the National Numbering Plan, are regulated by the Info-communications Media Development Authority (IMDA). Due to the small geographical size of Singapore, there are no area or trunk codes; all numbers belong to one numbering area, and thus come in the same 8-digit format. Numbers are categorised based on the first digit, thus providing ten possible categories, of which six are currently in use and the remaining four reserved for future usage.

History Until 1985, subscribers' telephone numbers in Singapore were five and six digits. Five digits were introduced in 1960s, whereas 5-digit and 6-digit phone numbers were introduced in 1960s as fixed lines grew, but in that year, these changed to seven digits as the introduction of new towns arose (Tampines, Jurong East, Bukit Batok, Yishun and Hougang) and a large number of new numbers were required. Rationalisation was based on geographical locale over the 12 years. On 1 September 1995, the digit '9' was added to the front of mobile and pager numbers, making numbers eight digits, and on 1 March 2002, the digit '6' was added to the front of existing fixed line telephone numbers. The migration to the 8-digit numbering plan was planned to be on 2002, ahead of 2004 deadline. Full telecommunication liberalisation in April 2000 led to rapid growth in the market, resulting in increased demand in numbers. The implementation of 8-digit numbering plan, ensured that there would be a sufficient number resource pool to cater to the expanded telecommunication services. Preparation work started in 1999, as an effective approach had to be worked out for the implementation, with minimum service disruption and inconvenience to customers. The public telecommunication service providers - SingTel and StarHub, implemented the 8-digit numbering plan and ensure smooth service continuity for their customers after the migration. There was a parallel run of 7-digit and 8-digit numbers from 1 March 2002 to 31 March 2002. From 1 April 2002 to 30 June 2002, those calling the 7-digit numbers would hear the number change announced, prompting them to add the digit "6" to the old number, after which the call would be disconnected. After 30 June, callers would hear the announcement that the number was unavailable. In March 2004, in response to the growing mobile phone numbering in Singapore, 8-digit mobile phone numbers starting with the digit "8" were introduced. In 2005, Infocomm Development Authority, the regulating authority at that time, introduced a policy framework which would govern IP telephony services, while introducing 8-digit phone numbers starting with the digit '3' for such services at the same time.

Calls to Malaysia and Indonesian border towns Until 1995, calls to Malaysia from Singapore were direct and similar to domestic phone calls, with only the area code for fixed line or Malaysian mobile phone code and number being required, hence 03 for Kuala Lumpur fixed line or 019 for Celcom mobile carrier were dialed instead of +60 3 and +60 19. In 1995, owing to the divergence of the two countries' numbering plans, the Subscriber Trunk Dialling prefix 020 was adopted. For example, in order to call a number in Kuala Lumpur, 020 is dialled first, followed by the area code 3 (excluding the leading zero), then the subscriber number. Similarly, calls to Batam, Samarinda, Pekanbaru and Tanjung Pinang in Indonesia require only the code 011, followed by the area code (minus '0') and the subscriber's number, hence to call a number in Batam from Singapore, a subscriber would dial 011 778 xxx xxx, instead of the international code +62 778. Calls to the rest of Indonesia, including those to mobile phones, require international dialling. Following the liberalization of the telecommunications industry, new carriers are assigned new carrier-specific codes for international and regional trunk call services. The codes 020 and 011 are assigned to the incumbent carrier SingTel. The other two major carriers, M1 and StarHub, do not offer any special dialling arrangements for calling to Malaysia and Indonesia, instead requiring full international dialling, the same as calling other countries.

Numbering scheme and format x denotes 0 to 9 y denotes 0 to 8 only

Number ranges 3xxx xxxx - Business and Corporate IP Telephony Services or VOIP line numbers. 6xxx xxxx - Public Switched Telephone Network (PSTN) and Residential IP Telephony Services 8xxx xxxx - Mobile, Data Services, New Numbers and Prepaid Numbers 9yxx xxxx - Mobile, Data Services and Prepaid Numbers (Pagers Until May 2012)

Special service numbers 800 xxx xxxx - Toll-free international services 1800 xxx xxxx - Toll-free domestic services (Free if calling from a landline. Airtime charges apply if calling from a mobile line. '1800' is alias for '6'; as such these services can be reached as toll numbers, including from outside of Singapore, by replacing '1800 xxx xxxx' with '+65 6xxx xxxx'.) 1900 xxx xxxx - Premium rate services

Short codes 0xx - International access codes 13xx - Voicemails 16xx - Service providers' customer services 1777 - Non-emergency ambulance 1799 - ScamShield Helpline 18xx - International calling card access numbers 993 - Ministry of Health's special ambulance service - previously used for suspected cases of H1N1, SARS and COVID-19 995 - Singapore Civil Defence Force - Fire or Emergency Ambulance 999 - Police 70995 - Emergency SMS (For immediate fire/ambulance assistance if it is not safe to talk) 70999 - Emergency SMS (For immediate police assistance if it is not safe to talk)

Telephone exchanges This is the list of telephone exchanges in Singapore. They also share the telephone exchanges with OpenNet locations, cable TV and '6'-regoed phone lines (each from SingTel and StarHub).

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Telephone numbers in Singapore

Start with the simplest possible case. Write down what Telephone numbers in Singapore claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Telephone numbers in Singapore before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Telephone numbers in Singapore ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Telephone numbers in Singapore

In research: Telephone numbers in Singapore appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Telephone numbers in Singapore in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Telephone numbers in Singapore is common in secondary-school and first-year university syllabi. It links to neighbouring topics Singapore communications-related lists, Telecommunications in Singapore, Telephone numbers by country, so understanding it makes those chapters shorter.
In everyday life: Look for Telephone numbers in Singapore outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Telephone numbers in Singapore in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Telephone numbers in Singapore means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Telephone numbers in Singapore out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Telephone numbers in Singapore in simple terms?

Why does Telephone numbers in Singapore matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Telephone numbers in Singapore?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Telephone numbers in Singapore.