Fractions: Halves, Quarters, and Thirds
6 lessons
Concepts
This study delivers 1 primary concept and 1 secondary concept.
Primary concept: Fractions as 'fractions of': 1/3, 1/4, 2/4, 3/4 (MA-Y2-C012)
Type: Knowledge | Teaching weight: 3/6Year 2 extends the set of fractions pupils can find and name from halves and quarters (Year 1) to include thirds and three-quarters. Pupils use fractions to describe a part of a discrete quantity (e.g. 1/3 of 12 = 4) or a continuous quantity (e.g. 1/3 of a length). A quarter of a quantity is one of four equal parts; two quarters (2/4) is two of those four equal parts; three quarters (3/4) is three of those four equal parts. Three-quarters is explicitly the first non-unit fraction pupils encounter. Mastery means pupils can find any of these fractions of given quantities and lengths, and write the fraction notation correctly.
Teaching guidance: Use sharing as the primary concrete approach: to find 1/3 of 12, share 12 equally among 3 (each person gets 4). To find 3/4 of 12, first find 1/4 (share among 4 = 3), then multiply by 3 (three-quarters = 3 groups of the unit fraction = 9). Use fraction strips and number lines to show fractions of continuous quantities. The curriculum specifies that pupils should count in fractions up to 10 on the number line (1 1/4, 1 2/4, 1 3/4, 2...) to understand fractions as numbers in their own right. Write fraction notation clearly: the vinculum (fraction bar) separates numerator and denominator. Key vocabulary: fraction, third, quarter, three-quarters, numerator, denominator, unit fraction, non-unit fraction, equal parts, whole Common misconceptions: Pupils frequently confuse the denominator with the number of shaded parts, rather than the total number of equal parts. When finding fractions of quantities by sharing, pupils may share unequally and not recognise the error. For three-quarters, pupils often do not connect this to 3 × (1/4) — they see it as a new fraction to memorise rather than as three unit fractions combined. Writing fraction notation is confused: some pupils write the numerator below the line.Differentiation
| Level | What success looks like | Example task | Common errors |
| Entry | Finding one half and one quarter of a small quantity by physically sharing objects equally. | Find half of 10 by sharing 10 counters equally between 2 plates. Find a quarter of 8 by sharing between 4 plates. | Sharing between the wrong number of groups (sharing between 4 when finding a half); Sharing unequally and not noticing |
| Developing | Finding 1/3, 1/4, 2/4 and 3/4 of quantities using sharing or by finding the unit fraction first then multiplying. | Find 3/4 of 12. | Finding 1/4 correctly but not knowing how to get to 3/4; Dividing by 3 instead of 4 to find a quarter (1/4 of 12 = 4 instead of 3) |
| Expected | Finding unit and non-unit fractions of quantities and lengths, and counting in fractions on a number line. | Count in quarters from 0 to 2 on the number line: 0, 1/4, 2/4, 3/4, 1, ... What is 1/3 of 18? | Not knowing that 4/4 = 1 whole, so stopping at 3/4 and jumping to 1; Confusing 1/3 with 1/4 when computing fractions of quantities |
Model response (Entry): Half of 10 is 5 (each plate gets 5). A quarter of 8 is 2 (each plate gets 2).
Model response (Developing): First find 1/4 of 12 = 3. Then 3/4 = 3 × 3 = 9. So 3/4 of 12 is 9.
Model response (Expected): 0, 1/4, 2/4, 3/4, 1, 1 1/4, 1 2/4, 1 3/4, 2. One third of 18 is 6.
Representation stages (CPA)
| Stage | Description | Resources | Transition cue |
| Concrete | Children find fractions of quantities by sharing objects equally between the denominator number of plates or cups. For 1/3 of 12: share 12 counters between 3 plates (4 each). For 3/4 of 12: share 12 between 4 plates (3 each), then count 3 of the 4 plates (9). | Counters, Plates or cups for sharing (2, 3 and 4), Fraction strips | Child shares objects equally between the correct number of groups to find unit fractions (1/3, 1/4) and then counts the appropriate number of groups for non-unit fractions (2/4, 3/4). |
| Pictorial | Children use fraction strips, fraction walls and number lines to find fractions of quantities and lengths. They draw sharing diagrams for 1/3, 1/4, 2/4 and 3/4 of given quantities, and count in fractions on number lines (0, 1/4, 2/4, 3/4, 1, 1 1/4...). | Fraction strips, Fraction walls, Number lines marked in fractions, Sharing diagram templates | Child uses fraction strips and drawn diagrams to find any of the required fractions (1/3, 1/4, 2/4, 3/4) of quantities up to 30, and counts in fractions along a number line beyond 1. |
| Abstract | Children find fractions of quantities mentally by dividing by the denominator and multiplying by the numerator. They write fraction notation correctly and count in fractions on a number line, understanding fractions as numbers that can exceed 1. | Fraction notation reference: numerator, denominator, vinculum | Child finds fractions of quantities mentally by dividing then multiplying, writes the fraction notation correctly (numerator above vinculum, denominator below), and explains the method in their own words. |
Secondary concept: Fraction equivalence: 2/4 = 1/2 (MA-Y2-C013)
Type: Knowledge | Teaching weight: 3/6The recognition that 2/4 and 1/2 name the same quantity — the same point on the number line, the same part of a whole — is the first exposure to fraction equivalence in the national curriculum. This is conceptually significant: two fractions with different numerators and denominators can have the same value. Mastery means pupils understand why 2/4 = 1/2 (because two of four equal parts is the same as one of two equal parts), and can identify this equivalence in different contexts.
Differentiation
| Level | What success looks like | Common errors |
| Entry | Comparing folded paper strips to see that 1/2 and 2/4 cover the same area. | Saying they are different because '1 is not the same as 2'; Folding unevenly so the comparison is not accurate |
| Developing | Recognising 2/4 = 1/2 on a number line and using fraction walls to verify the equivalence. | Placing 2/4 at a different point from 1/2 on the number line; Thinking 2/4 means '2 and 4' rather than '2 out of 4' |
| Expected | Explaining why 2/4 = 1/2 and recognising that equivalent fractions name the same value. | Knowing the fact by rote ('Miss told us') without understanding why; Thinking all fractions with a 2 on top are equal to 1/2 |
Thinking lens: Scale, Proportion and Quantity (primary)
Key question: How big, how many, or how much — and how does that change how we think about it? Why this lens fits: Finding fractions of shapes and sets is directly about proportional part-whole reasoning — a half is always the same proportion regardless of the size of the whole, which is why 2/4 = 1/2. Question stems for KS1:Session structure: Practical Application + Worked Example Set
This study uses 2 vehicle templates:
Practical Application (main structure)
A hands-on sequence where pupils apply knowledge and skills to solve a practical problem or create a functional outcome. Begins with a real-world context, builds skills through rehearsal, guides design or planning, supports making or problem-solving, and concludes with evaluation against success criteria.
context → skill_rehearsal → design → make_or_solve → evaluate
Assessment: Practical outcome (solution, product, program) evaluated against defined success criteria, with written or verbal explanation of the process and decisions made.
Worked Example Set
A mastery-oriented mathematics sequence moving through the concrete-pictorial-abstract progression with activation and reasoning extension phases. Begins by activating prior knowledge, introduces new concepts with physical manipulatives, transitions to pictorial representations, develops abstract fluency, applies in context, and extends through reasoning challenges.
activation → concrete → pictorial → abstract → application → reasoning_extension
Assessment: Graduated practice set moving from guided examples to independent application, with reasoning task requiring explanation of method and justification of answers.
Teacher note: Use the WORKED EXAMPLE SET template: begin by activating what children already know using a quick warm-up. Introduce new concepts using physical objects they can touch and move. Move to pictures and drawings that represent the same idea. Then show how to record it using numbers and symbols. Let children practise with similar examples and talk about their thinking.
KS1 question stems:
Why this study matters
Y2 extends fraction understanding from halves and quarters to include thirds, and from unit fractions to non-unit fractions (2/4, 3/4). The critical new idea is that 2/4 is equivalent to 1/2 -- this is the first encounter with fraction equivalence. Fractions of quantities (1/3 of 12) connect fractions to division. Concrete folding and sharing remain essential, but pupils now also work with fraction notation and begin to reason about the relationship between fractions.
Pitfalls to avoid
Mathematical reasoning skills (KS1)
These disciplinary skills should be woven through teaching, not taught in isolation:
Vocabulary word mat
| Term | Meaning |
| 1/2 | A fraction meaning one part out of two equal parts; represents one half of a whole. |
| 2/4 | A fraction meaning two parts out of four equal parts; equivalent to one half. |
| denominator | The bottom number in a fraction, showing how many equal parts the whole has been divided into. |
| different names | Different ways of expressing the same value, such as 1/2, 2/4, and 50%, which are all names for the same amount. |
| equal | The same in amount, size, or value. |
| equal parts | Pieces of a whole that are all exactly the same size. |
| equivalent | Having the same value, even though it looks different. |
| fraction | A number that represents part of a whole or part of a group, written with a numerator over a denominator. |
| fraction wall | A visual display showing rows of equal-length bars divided into different fractions, used to compare and find equivalences. |
| non-unit fraction | A fraction where the numerator is greater than 1, representing more than one equal part. |
| number line | A straight line marked with numbers at equal intervals, used for counting, adding, and subtracting. |
| numerator | The top number in a fraction, showing how many of the equal parts are being counted. |
| quarter | One of four equal parts of a whole. |
| same | Equal or identical in value, size, or amount. |
| third | One of three equal parts of a whole, written as 1/3. |
| three-quarters | Three out of four equal parts of a whole, written as 3/4. |
| unit fraction | A fraction with a numerator of 1, representing one equal part of a whole (e.g. 1/2, 1/3, 1/4). |
| whole | The complete thing before it is divided into parts. |
Prior knowledge (retrieval plan)
Pupils should already know the following from earlier units:
| Prior knowledge needed | For concept | Description |
| Recognising one half | Fractions as 'fractions of': 1/3, 1/4, 2/4, 3/4 | One half is the first fraction pupils encounter formally and is defined as one of two equal parts... |
| Recognising one quarter | Fractions as 'fractions of': 1/3, 1/4, 2/4, 3/4 | One quarter is the second fraction pupils encounter and is defined as one of four equal parts. Pu... |
Scaffolding and inclusion (Y2)
| Guideline | Detail |
| Reading level | Emergent Reader |
| Text-to-speech | Required |
| Max sentence length | 10 words |
| Vocabulary | Common concrete nouns plus simple abstractions (e.g., feelings, seasons, simple cause/effect). High-frequency words accessible. Subject vocabulary must be spoken and displayed simultaneously. |
| Scaffolding level | Maximum |
| Hint tiers | 2 tiers |
| Session length | 8–15 minutes |
| Worked examples | Required — Narrated with text displayed. Character models the thinking. Pause points for child to predict next step. |
| Feedback tone | Warm Encouraging |
| Normalize struggle | Yes |
| Example correct feedback | You heard the /ee/ sound hiding in the middle — that is tricky to spot! |
| Example error feedback | That is the short /u/ sound. The one we are looking for is /ee/, like in tree. Can you hear the difference? |
Access and Inclusion
Likely barriers
This study has high demands on: Vocabulary Novelty (Fraction vocabulary introduces 'numerator', 'denominator', 'third', 'quarter', 'equal parts', and 'fraction of' — all new mathematical terms that describe relationships rather than objects.), Abstractness Without Concrete Anchor (Fractions as 'fractions of' (1/3, 1/4, 2/4, 3/4) require understanding part-whole relationships with multiple different denominators. Each denominator represents a different equal-sharing scenario. Without extensive concrete partitioning experience, the notation is meaningless.).
Universal supports
Apply by default for all learners:
Targeted options
Use with caution
Knowledge organiser
Core facts (expected standard):Graph context
Node type:MathsTopicSuggestion | Study ID: MTS-KS1-011
Concept IDs:
MA-Y2-C012: Fractions as 'fractions of': 1/3, 1/4, 2/4, 3/4 (primary)MA-Y2-C013: Fraction equivalence: 2/4 = 1/2``cypher
MATCH (ts:MathsTopicSuggestion {suggestion_id: 'MTS-KS1-011'})
-[:DELIVERS_VIA]->(c:Concept)
-[:HAS_DIFFICULTY_LEVEL]->(dl)
RETURN c.name, dl.label, dl.description
``
Generated from the UK Curriculum Knowledge Graph — zero LLM generation.