AC9M3N02
Official content description
recognise and represent unit fractions including 1/2, 1/3, 1/4, 1/5 and 1/10 and their multiples in different ways; combine fractions with the same denominator to complete the whole
What AC9M3N02 actually looks like when you teach it
Unit fractions are where a lot of children's mathematics quietly goes wrong, because the whole-number rules they've spent three years learning stop applying. Keep everything concrete for longer than feels necessary — fraction strips, folded paper, a number line from 0 to 1. Two ideas need to land: the denominator counts how many equal parts the whole was cut into, and the more parts you cut, the smaller each one is. Combining fractions with the same denominator to make a whole comes naturally from the strips: three thirds is the whole strip back again.
What the class will get wrong — and what to do about it
The error
Ordering unit fractions by their denominators, so 1/5 is judged larger than 1/3 because 5 is larger than 3.
How to confront it
Have them fold and compare the strips physically, then line the strips up under one another. Ask the question in a context they can't argue with: would you rather have a third of a pizza or a fifth of it?
Ready to put on the board
We are learning to represent unit fractions and combine fractions with the same denominator.
- I can show 1/2, 1/3, 1/4, 1/5 and 1/10 in more than one way.
- I can explain why 1/3 is bigger than 1/5.
- I can combine fractions with the same denominator to make a whole.
The fraction wall we build ourselves
- Keep one strip whole and label it 1. This is the rule for the whole activity: every strip started the same size.
- Fold the next into halves, the next into quarters, then thirds, fifths and tenths. Label every part.
- Glue the strips one under another, left edges aligned, to make a wall.
- Now ask the ordering questions against their own wall: which is bigger, 1/4 or 1/5? How many fifths make the whole?
- Finish by shading 3/5 on the fifths strip and asking how much more is needed to complete the whole.
Free to use in your classroom. Written for AC9M3N02, not adapted from another year level.
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The Year 3 Maths planning scaffold
A one-page planning sheet with the official achievement standard, every content description grouped by strand, and space for your assessment and week-by-week sequence. Print it and plan on paper, or use it as the skeleton for a unit.
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What Year 3 Maths students should achieve
Coverage is judged against the achievement standard — not by ticking every content description. These are the official Year 3 Maths standard sentences this code builds towards:
- Students conduct guided statistical investigations involving categorical and discrete numerical data, and interpret their results in terms of the context.
- They use mathematical modelling to solve practical problems involving single-digit multiplication and division, recalling multiplication facts for twos, threes, fours, fives and tens, and using a range of strategies.
- They create algorithms to investigate numbers and explore simple patterns.
- Students represent unit fractions and their multiples in different ways.
- Students use familiar metric units when estimating, comparing and measuring the attributes of objects and events.
- By the end of Year 3, students order and represent natural numbers beyond 10 000.
The Number progression either side of AC9M3N02
A class can only meet this descriptor if they were taught the one before it. If yours hasn't, that's where the lesson starts — not here.
Taught before · Year 2
- AC9M2N01recognise, represent and order numbers to at least 1000 using physical and virtual materials, numerals and number lines
- AC9M2N02partition, rearrange, regroup and rename two- and three-digit numbers using standard and non-standard groupings; recognise the role of a zero digit in place value notation
- AC9M2N03recognise and describe one-half as one of 2 equal parts of a whole and connect halves, quarters and eighths through repeated halving
Builds towards · Year 4
- AC9M4N01recognise and extend the application of place value to tenths and hundredths and use the conventions of decimal notation to name and represent decimals
- AC9M4N02explain and use the properties of odd and even numbers
- AC9M4N03find equivalent representations of fractions using related denominators and make connections between fractions and decimal notation
Other Year 3 Number codes
- AC9M3N01recognise, represent and order natural numbers using naming and writing conventions for numerals beyond 10 000
- AC9M3N03add and subtract two- and three-digit numbers using place value to partition, rearrange and regroup numbers to assist in calculations without a calculator
- AC9M3N04multiply and divide one- and two-digit numbers, representing problems using number sentences, diagrams and arrays, and using a variety of calculation strategies
- AC9M3N05estimate the quantity of objects in collections and make estimates when solving problems to determine the reasonableness of calculations
- AC9M3N06use mathematical modelling to solve practical problems involving additive and multiplicative situations including financial contexts; formulate problems using number sentences and choose calculation strategies, using digital tools where appropriate; interpret and communicate solutions in terms of the situation
- AC9M3N07follow and create algorithms involving a sequence of steps and decisions to investigate numbers; describe any emerging patterns
Content description and achievement standard © Australian Curriculum, Assessment and Reporting Authority (ACARA), Australian Curriculum Version 9, used under CC BY 4.0. TeachKoala is not affiliated with or endorsed by ACARA.