AC9M4N02 • Year 4 Maths
Explain and use the properties of odd and even numbers.
An even number can be arranged into pairs with no remainder; an odd number leaves one unpaired. Whether a whole number is odd or even is called its parity. This follows predictable patterns under addition, subtraction and multiplication.
Learning routine: Pair the quantity → Identify parity → Test an operation → Generalise → Justify
Nine is odd because four pairs can be made and one object remains unpaired. A final digit of 0, 2, 4, 6 or 8 identifies an even whole number.
Explain patterns using pairs, not only examples. Two unpaired objects from odd + odd join to form another pair.
For addition, combine paired collections and inspect the leftovers. For multiplication, an even-sized group consists only of complete pairs; repeating it preserves those pairs. For odd × odd, the odd number of single leftovers has one left after pairing.
This explanation works for any two odd whole numbers: their pairs stay paired and their two leftovers pair with each other.
| Starting and removed amounts | Result | Example |
|---|---|---|
| Even − even | Even | 18 − 6 = 12 |
| Odd − odd | Even | 17 − 5 = 12 |
| Even − odd | Odd | 18 − 5 = 13 |
| Odd − even | Odd | 17 − 6 = 11 |
Keep the results as whole numbers here. Removing an even amount removes complete pairs; removing an odd amount also removes one unpaired item or breaks a pair.
Worked trace: 354 ends in 4 → Yes → Even. 731 ends in 1 → No → Odd. Applied to 0, 18, 25 and 42, the Even branch keeps 0, 18 and 42. Zero belongs here: it makes two groups of zero with none left over.
If someone writes 62 + 28 = 89, reject it: even + even must be even, while 89 is odd. But an even proposed answer is not automatically correct: 62 + 28 = 88 also has the required parity but is wrong. Calculate the exact sum, 90, to finish the check.
Content description: explain and use the properties of odd and even numbers.
Use counters to model 13, 14 and 15, then record the number of pairs and whether one remains.
Test several odd and even additions, then write a general rule and explain it with pairing.
Predict whether each result is odd or even, then use a calculation to check. 4 382 + 7 915 is odd (even + odd); 326 × 47 is even (an even factor); 9 999 − 624 is odd (odd − even). Their exact values are 12 297, 15 322 and 9 375.
Core idea: An even number can be arranged into pairs with no remainder; an odd number leaves one unpaired. Whether a whole number is odd or even is called its parity. This follows predictable patterns under addition, subtraction and multiplication.
Teach with the Topic Guide and Classroom View, then use the worksheet, Practice and Test.
Support: physically pair counters and share whole objects between two. Core: explain all addition, subtraction and multiplication cases and follow the decision flowchart. Extend: find a counterexample to a false claim or explain a pattern with several addends. Keep the work on whole numbers; do not assume division has the same fixed rules as multiplication.
Mastery evidence: Students justify parity using ones digits, pairs, arrays or a clear counterexample, not by guessing from the first digit.
Open Classroom View and expand one section at a time to project the models and worked examples.
Open Classroom View| Australia | Australian Curriculum v9.0 | AC9M4N02 |
| Victoria | Victorian Curriculum F–10 | Year 4 Number: number properties. |
| NSW | NSW Curriculum | Stage 2 Mathematics: whole-number properties. |
The SkillrHub lesson remains the primary learning resource. This optional video reinforces the explanation; you can complete the lesson and practice without watching.
Before you watch:
Scratch Garden — Refresh the odd-number pattern before investigating odd and even properties.
As you watch: Which last digits repeat as the odd numbers grow?
Load video player Loads YouTube in this lesson. See the video notice below.
Try it: Choose two odd numbers and add them. Make pairs with counters to explain why their sum is even.
Video unavailable, inaccurate or unsuitable for this year? Report a video problem to SkillrHub by email. You can continue with the written lesson and practice resources.
Videos are curated from trusted independent educational creators and played through YouTube. Rights remain with their respective owners. Inclusion does not imply that a creator or YouTube endorses SkillrHub.
YouTube’s terms and privacy policy apply to its player. Advertising, recommendations and external links may appear, and videos may change or become unavailable. SkillrHub’s written lessons and practice resources remain available separately.
To report a content, suitability or rights concern, email skillrhublearning@gmail.com with the lesson code and video link. Please do not include personal student information.
Mapped skill: explain and use the properties of odd and even numbers
These references identify matching or closely related learning. Curriculum sequence, terminology and depth vary, so teachers should use the mapped skill and lesson difficulty to confirm suitability.
| Region | Curriculum framework | Closest level or code |
|---|---|---|
| Australia | Australian Curriculum v9.0 | AC9M4N02 · Year 4 |
| Victoria | Victorian Curriculum F–10 Version 2.0 — Mathematics | VC2M4N02 · Level 4 |
| New South Wales | NSW Mathematics K–10 Syllabus (2022) | MA2-RN-01 · Stage 2 |
| United States (USA) | Common Core State Standards for Mathematics | Grade 4 |
| Canada (Ontario) | Ontario Curriculum — Mathematics | Grade 4 |
| United Kingdom (England) | National Curriculum in England — Mathematics | Year 5, Key Stage 2 |
| India | NCERT / CBSE — Mathematics | Class 4 |
Australian Curriculum v9.0 is the canonical source for this SkillrHub lesson. Victoria and NSW entries name the closest published state codes or outcomes; international entries are planning references rather than claims of identical curricula.
Help improve SkillrHub
Ask about this lesson, suggest an improvement or report an error. Facebook opens only when you choose an option below.
Topic reference: AC9M4N02 — AC9M4N02: Odd and even numbers
Privacy: Please don’t share personal student or school information. Younger students should ask a parent, guardian or teacher to post on their behalf.