Mathematics KS2 Y6 Mandatory

Ratio and Proportion

Subject
Mathematics
Key Stage
KS2
Year group
Y6
Statutory reference
NC Y6 Ratio and Proportion: solve problems involving the relative sizes of two quantities where missing values can be found by using integer multiplication and division facts
Source document
Mathematics (KS1/KS2) - National Curriculum Programme of Study
Status
Mandatory
Status: Mandatory

Concepts

This study delivers 1 primary concept and 0 secondary concepts.

Primary concept: Ratio and Proportion (MA-Y6-C012)

Type: Process | Teaching weight: 3/6

Mastery of ratio and proportion means pupils can express the relationship between two quantities using ratio notation (a:b), scale up and down using a multiplier, solve problems involving sharing in a given ratio, and use percentages and fractions as tools for expressing proportional relationships. A fully secure pupil understands the difference between additive comparison (A has 3 more than B) and multiplicative comparison (A has 3 times as many as B) and can identify which type of reasoning is required by a problem.

Teaching guidance: Begin with practical activities: making paint colours from different proportions of red and yellow, mixing squash with water, dividing a class into boys and girls in a given ratio. The 'unitary method' — finding the value of one part and scaling — should be taught alongside the 'scale factor' method. Bar models are particularly effective for ratio problems as they make the proportional structure visible. Connect to percentage increase and decrease as applications of proportion. Similar shapes provide a geometric context in which scale factors arise naturally. Key vocabulary: ratio, proportion, scale factor, unitary method, parts, share, for every, in the ratio, percentage, similar Common misconceptions: Pupils frequently apply additive rather than multiplicative reasoning in proportion problems (e.g., if a recipe for 4 serves uses 200 g flour and 150 g butter, pupils subtract to get 50 g 'difference' and add 50 g for each extra serving rather than using the ratio 4:3). In sharing problems, pupils sometimes give each person the stated number of parts rather than computing the value of each part. The bar model is the most effective tool for preventing both misconceptions.

Differentiation

LevelWhat success looks likeExample taskCommon errors

EntrySharing a quantity in a simple ratio using the 'one part' method with concrete or pictorial support.Share 20 sweets between Ali and Ben in the ratio 3:2. How many does each person get?Dividing 20 by 3 and 20 by 2 separately (getting 6.67 and 10); Not finding the total number of parts first
DevelopingSolving proportion problems using the unitary method or scale factor, including simple recipes and scaling.A recipe for 4 people uses 300g flour. How much flour for 6 people?Adding 2 people worth of flour by adding 2 × 75 = 150 to 300 = 450 (correct result, but additive reasoning can fail in harder cases); Using additive reasoning: 6 is 2 more than 4, so add 2 × 50 = 100g more (wrong)
ExpectedSolving ratio and proportion problems involving missing values, including percentage contexts, using multiplicative reasoning.In a class, the ratio of boys to girls is 3:5. There are 15 girls. How many children are in the class altogether?Adding 3 to 15 instead of finding the multiplier (saying 18 children); Not finding the value of one part before scaling
Greater DepthSolving multi-step ratio problems where the ratio must be inferred from context, or where a change in one quantity requires reasoning about the effect on the ratio.Purple paint is made by mixing red and blue in the ratio 3:5. Sam has 600 ml of purple paint. He adds 150 ml more red paint. What is the new ratio of red to blue? Give your answer in its simplest form.Adding 150 ml to the total and re-splitting in the original ratio (not understanding only red changed); Simplifying 375:375 as 3:3 instead of 1:1

Model response (Entry): Total parts: 3 + 2 = 5. One part = 20 ÷ 5 = 4. Ali gets 3 × 4 = 12. Ben gets 2 × 4 = 8.
Model response (Developing): For 1 person: 300 ÷ 4 = 75g. For 6 people: 75 × 6 = 450g.
Model response (Expected): Girls represent 5 parts. 5 parts = 15, so 1 part = 3. Boys = 3 parts = 9. Total: 15 + 9 = 24.
Model response (Greater Depth): Original: 3 + 5 = 8 parts. One part = 600 ÷ 8 = 75 ml. Red = 3 × 75 = 225 ml. Blue = 5 × 75 = 375 ml. After adding red: 225 + 150 = 375 ml red. Blue stays at 375 ml. New ratio = 375:375 = 1:1.

Representation stages (CPA)

StageDescriptionResourcesTransition cue

ConcreteMixing paint, juice or recipe ingredients in given ratios, physically sharing objects into ratio groups using sorting trays, and using Cuisenaire rods to show proportional relationshipssorting trays, counters (two colours), Cuisenaire rods, measuring jugs (for mixing), recipe cardsChild finds the value of one part by dividing by the total number of parts and scales correctly without physical objects
PictorialDrawing bar models to represent ratios, recording ratio tables showing scaling, and solving proportion problems on paperbar model template, ratio table template, squared paperChild solves ratio and proportion problems on paper using bar models or the unitary method, selecting the most efficient approach
AbstractSolving ratio and proportion problems mentally, using the unitary method and scale factors, and distinguishing multiplicative from additive relationshipsChild solves any ratio/proportion problem efficiently and always identifies whether a problem requires multiplicative or additive reasoning


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: Ratio and proportion are the formal language of multiplicative comparison — this cluster teaches pupils to express and use relative quantities directly, bridging all prior fraction and multiplicative work to KS3 Ratio, Proportion and Rates of Change. Question stems for KS2:
  • How many times bigger is this than that?
  • What fraction of the whole is this part?
  • Which unit of measurement fits best here? Why?
  • If we doubled the amount, what would change?

  • Session structure: Worked Example Set + Practical Application

    This study uses 2 vehicle templates:

    Worked Example Set (main structure)

    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.

    activationconcretepictorialabstractapplicationreasoning_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: activate prior knowledge and address common misconceptions. Guide pupils through the concrete-pictorial-abstract progression, modelling each step with clear mathematical language. Provide varied practice that builds fluency, then extend with reasoning problems that require pupils to explain, justify, or spot errors. Use bar models and diagrams to build conceptual understanding. KS2 question stems:
  • What do you already know that could help you here?
  • Can you draw a bar model or diagram to represent this problem?
  • Where has this gone wrong, and how would you correct it?
  • Can you explain why this method works, not just how?
  • Practical Application

    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.

    contextskill_rehearsaldesignmake_or_solveevaluate Assessment: Practical outcome (solution, product, program) evaluated against defined success criteria, with written or verbal explanation of the process and decisions made. Teacher note: Use the PRACTICAL APPLICATION template: set a real-world context or problem that requires pupils to apply knowledge and skills. Rehearse the key skills needed through guided practice. Support pupils in designing their approach, carrying out the practical task, and evaluating their outcome. Encourage them to explain what worked well and what they would improve. KS2 question stems:
  • What skills will you need to solve this problem?
  • What is your plan, and why did you choose this approach?
  • How well did your solution work?
  • What would you change if you did it again?

  • Mathematical reasoning skills (KS2)

    These disciplinary skills should be woven through teaching, not taught in isolation:

  • Checking and verifying results — Use inverse operations, estimation or an alternative method to check whether a result is reasonable, and adjust working when an answer does not make sense in context.
  • Problem solving with unfamiliar and complex structures — Formulate and solve problems that require choosing from a wide range of mathematical knowledge, devising strategies for problems with no immediately obvious method, and persevering through multi-stage solutions in unfamiliar contexts.
  • Mathematical proof — Understand and apply the concept of mathematical proof, distinguishing between evidence, conjecture and proof, constructing simple proofs by exhaustion or direct argument, and recognising why a finite number of examples cannot prove a universal statement.
  • Critical evaluation and error analysis — Critically evaluate the validity of mathematical arguments and solutions presented by others, identifying errors in reasoning or calculation, explaining why a result is or is not correct, and constructing counter-examples to disprove false claims.
  • Algebraic reasoning and generalisation — Express generalisations symbolically using algebraic notation, reason about the properties of unknown quantities, and use algebra to prove or disprove conjectures about numbers and geometric relationships.
  • Estimation, checking and reasonableness — Use rounding, inverse operations and known facts to estimate answers before calculating, check the reasonableness of results in context, and identify errors in worked examples by comparing expected and actual outcomes.

  • Vocabulary word mat

    TermMeaning

    for everyA phrase used to express a ratio relationship, describing proportional correspondence between quantities.
    in the ratioA phrase describing the proportional relationship between two or more quantities.
    partsThe pieces that make up a whole; in fractions, the equal sections of a divided whole.
    percentageA way of expressing a number as a fraction of 100, used to compare proportions.
    proportionThe relative size of a part compared to the whole, often expressed as a fraction, decimal, or percentage.
    ratioA way of comparing two or more quantities, showing how much of one thing there is for every amount of another, written with a colon.
    scale factorThe number by which all dimensions of a shape are multiplied to enlarge or reduce it.
    shareTo divide a quantity equally among a group.
    similarHaving the same shape but not necessarily the same size; corresponding angles are equal and sides are proportional.
    unitary methodA strategy for solving proportion problems by first finding the value of one unit, then scaling up.

    Prior knowledge (retrieval plan)

    Pupils should already know the following from earlier units:

    Prior knowledge neededFor conceptDescription

    Measuring angles in degrees using a protractorRatio and ProportionAngles are measured in degrees (°). A full turn is 360°; a right angle is 90°; a straight line is...


    Assessment alignment (KS2)

    KS2 test framework content domain codes assessed by this study:

    CodeDescriptionAssesses concept

    CDC-KS2-MA-6R1Year 6: relative sizes, similarityRatio and Proportion
    CDC-KS2-MA-6R2Year 6: use of percentages for comparisonRatio and Proportion
    CDC-KS2-MA-6R3Year 6: scale factorsRatio and Proportion
    CDC-KS2-MA-6R4Year 6: unequal sharing and groupingRatio and Proportion


    Scaffolding and inclusion (Y6)

    GuidelineDetail

    Reading levelProficient Reader (Lexile 600–800)
    Text-to-speechAvailable
    Max sentence length25 words
    VocabularyAcademic vocabulary expected without scaffolding. Literary vocabulary (connotation, imagery, personification) established. Etymology useful for unfamiliar vocabulary.
    Scaffolding levelLight
    Hint tiers4 tiers
    Session length25–40 minutes
    Worked examplesRequired — Student-completed faded examples. Text-based. Example solutions shown for comparison after independent attempt.
    Feedback toneIntellectual Peer
    Normalize struggleYes
    Example correct feedbackYour rhythmic analysis correctly identified the iambic pattern in lines 2 and 4, and you rightly noted the disruption in line 3. The question is: why might Shakespeare have broken the metre there?
    Example error feedbackThere is a problem with that interpretation: you suggested the character is happy at the end, but the meter becomes irregular in the final couplet — what might that irregularity signal about their emotional state?


    Knowledge organiser

    Core facts (expected standard):
  • Ratio and Proportion: Solving ratio and proportion problems involving missing values, including percentage contexts, using multiplicative reasoning.

  • Graph context

    Node type: MathsTopicSuggestion | Study ID: MTS-Y6-004 Concept IDs:
  • MA-Y6-C012: Ratio and Proportion (primary)
  • Cypher query:

    ``cypher

    MATCH (ts:MathsTopicSuggestion {suggestion_id: 'MTS-Y6-004'})

    -[: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.