Spotting the next number can feel like solving a small mystery. Explaining the rule is the more useful part: what changes each time, where does the sequence begin and does the proposed rule fit every term shown?
For families exploring schools in Pasir Ris, number patterns offer a practical connection between noticing, calculating and reasoning. Casuarina Primary’s published Mathematics approach provides a local example.
This guide uses original practice sequences, not school worksheets. It does not claim that a particular pattern is taught at a fixed year level or guarantee examination results.
eduKateSG · Neighbourhood education
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Explore the school context, try the small activity or check what it teaches.
1. Understand the context · 2. Try the activity · 3. Review and continue
Contents
Explore, practise and connect · Four chapters
CHAPTER 1 OF 4
1. See the local Mathematics connection
Casuarina Primary’s Mathematics page describes enjoyable learning, concrete and pictorial experiences, and opportunities for pupils to communicate their reasoning through collaborative work.
That gives families a specific question to ask: can a learner explain a pattern in a way that another person can check?
The independent sequence below is not a school activity. Follow current teacher guidance for classroom methods and match the size of the numbers to the learner’s understanding.
CHAPTER 2 OF 4
2. Compare neighbouring terms
Write this sequence: 5, 9, 13, 17. Calculate the difference between each pair of neighbouring terms: 9 − 5 = 4, 13 − 9 = 4 and 17 − 13 = 4.
A simple rule fitting these terms is “Start at 5 and add 4 each time.” If that rule continues, the next term is 21.
Notice that the explanation has two parts. “Add 4” describes the change, but “Start at 5” tells us where this particular sequence begins.
Ask the learner to check every displayed step. Looking only at the first two terms can hide a later change in the pattern.
CHAPTER 3 OF 4
3. Separate a term’s position from its value
Label the positions: term 1 is 5, term 2 is 9, term 3 is 13 and term 4 is 17. The position tells us where the term sits; its value tells us the number at that position.
Under the stated rule, term 5 is 21. From the first term to the fifth term, there are four increases, not five.
Counting the gaps makes that distinction visible. A child can draw a small arrow labelled +4 between each neighbouring pair rather than relying on a memorised shortcut.
For a learner ready for a longer example, term 10 is 5 + 9 × 4 = 41. Explain the nine increases before using the calculation.
CHAPTER 4 OF 4
4. State what is known and what is assumed
A finite list does not uniquely determine every future term unless a rule or context is supplied. In this exercise, continuing to add 4 is the stated assumption.
If someone proposes another rule, ask whether it matches all the displayed terms and what it predicts next. A rule that fits only the first step is not enough.
Try a different given rule: start at 2 and double each time. This produces 2, 4, 8, 16. The differences change, so the earlier add-4 explanation does not apply.
Finish with one sequence, its starting value, its rule and a checked next term. The aim is to make the reasoning visible, not simply reward the quickest guess.
Sources and scope
School information checked on 13 October 2026 (Singapore time): Casuarina Primary: Mathematics. Programmes may change. Family activities are independently written by eduKateSG, not official school tasks. This article does not imply school endorsement, rank schools or guarantee admission or learning results.