Pearson Edexcel · A-Level · Mathematics

    Course version: 9MA0 · Version from Mar 2026

    Mathematical modelling: Translate a situation in context into a…

    Full specification wording

    Overarching theme 3: Mathematical modelling: Translate a situation in context into a mathematical model, making simplifying assumptions.

    Mathematical modelling begins by translating a real context into mathematical form.

    Checked against the Pearson Edexcel 9MA0 specification (opens in a new tab) on .

    • Point 1 of 5
    • 4 key terms

    Study notes

    From the checked teaching notes for this specification point.

    The idea

    Mathematical modelling begins by translating a real context into mathematical form. You identify the key variables, choose suitable units, and state simplifying assumptions that make the problem tractable. For example, modelling a falling object: let h be height in metres and t time in seconds; assume no air resistance and constant gravitational acceleration g = 9.8 m s⁻². This gives h = h₀ − ½gt². The assumptions ignore air resistance and the variation of g with height. You must decide which features to include and which to neglect, then express relationships using functions, equations or graphs. The model is a simplification, not the reality, so assumptions must be explicit and justified in context.

    What earns the marks

    • Identifies the relevant variables and their units from the context, for example time in seconds and height in metres.
    • States clear simplifying assumptions, such as ignoring air resistance or treating acceleration as constant.
    • Translates the situation into a correct mathematical form, for example an equation, function or graph.
    • Justifies why each assumption is reasonable in the given context, linking to the scale or purpose of the model.
    • Uses appropriate notation and defines symbols consistently.

    Common mistakes and how to put them right

    • Omitting assumptions entirely: correct by explicitly listing each simplification and explaining its effect.

    • Using inconsistent or missing units.

      Put it right by stating units for every variable and checking dimensional consistency.

    • Including irrelevant variables that complicate the model.

      Put it right by identifying only the factors that materially affect the output.

    Exam tips

    • Underline the contextual quantities in the question before writing any equations.
    • Write assumptions as full sentences that name the factor being ignored and the reason.
    • Check that your mathematical expression reduces to a sensible result when extreme values are substituted.

    Try the lesson

    The start of the Overarching theme 3: Mathematical modelling: Translate a situation in context into a mathematical model, making simplifying assumptions. lesson, made from checked teaching notes for this specification point.

    Have a go first

    A cylindrical water tank has radius r metres and height h metres. Water flows in at a constant rate of 0.4 cubic metres per minute. Construct a model for the depth d, in metres, of water after t minutes, starting from an empty tank, and state one simplifying assumption needed.

    Listen

    Mathematical modelling begins by translating a real context into mathematical form. You identify the key variables, choose suitable units, and state simplifying assumptions that make the problem tractable. For example, modelling a falling object: let h be height in metres and t time in seconds; assume no air resistance and constant gravitational acceleration g = 9.8 m s⁻². This gives h = h₀ − ½gt². The assumptions ignore air resistance and the variation of g with height. You must decide which features to include and which to neglect, then express relationships using functions, equations or graphs. The model is a simplification, not the reality, so assumptions must be explicit and justified in context. A strong answer earns marks for these points. Identifies the relevant variables and their units from the context, for example time in seconds and height in metres. States clear simplifying assumptions, such as ignoring air resistance or treating acceleration as constant. Translates the situation into a correct mathematical form, for example an equation, function or graph. Justifies why each assumption is reasonable in the given context, linking to the scale or purpose of the model. A common slip: Using inconsistent or missing units. Instead, stating units for every variable and checking dimensional consistency. Exam tip: Underline the contextual quantities in the question before writing any equations.

    See it

    A top-down flowchart with six nodes. The first node, Real context, points to Identify key variables and units, which points to State simplifying assumptions, which points to Express relationships as functions, equations or graphs, which points to Mathematical model, which points to Justify assumptions in context.
    It shows the steps of mathematical modelling, from a real context through variables, assumptions and mathematical form to a justified model.

    Put it in order

    Put these steps in the order they happen.

    1. 1. State simplifying assumptions
    2. 2. Identify key variables and units
    3. 3. Real context
    4. 4. Justify assumptions in context
    5. 5. Mathematical model
    6. 6. Express relationships as functions, equations or graphs

    Key words

    Say what each word means before you turn the card.

    Mathematical model

    Try answering aloud or in your head before turning the card.

    Simplifying assumptions

    Try answering aloud or in your head before turning the card.

    Variables and units

    Try answering aloud or in your head before turning the card.

    Mathematical representation

    Try answering aloud or in your head before turning the card.

    See every definition
    Mathematical model
    A simplification, not the reality, obtained by translating a situation in context into mathematical form.
    Simplifying assumptions
    Statements that make the problem tractable, which must be explicit and justified in context.
    Variables and units
    The key quantities identified from the context, each given suitable units.
    Mathematical representation
    The expression of relationships using functions, equations or graphs.

    Label the diagram

    Some boxes have lost their names. Pick the right name for each number.

    The diagram again, with 3 boxes numbered instead of named. A top-down flowchart with six nodes. The first node, Real context, points to Identify key variables and units, which points to State simplifying assumptions, which points to Express relationships as functions, equations or graphs, which points to Mathematical model, which points to Justify assumptions in context.
    • 1Box 1

    • 2Box 2

    • 3Box 3

    0 of 3 labelled

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