Arithmetic Operations

    AQA
    GCSE

    Arithmetic operations constitute the fundamental processing capabilities of the Arithmetic Logic Unit (ALU) within the CPU. Candidates must demonstrate proficiency in applying standard operators (+, -, *, /) alongside integer-specific operations, specifically integer division (DIV) and modulus (MOD). Mastery requires the accurate application of operator precedence (BIDMAS/BODMAS) to evaluate complex expressions and an understanding of how these operations function across different data types, including the implications of truncation and precision in integer versus real number arithmetic.

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    Objectives
    3
    Exam Tips
    3
    Pitfalls
    4
    Key Terms
    4
    Mark Points

    What You Need to Demonstrate

    Key skills and knowledge for this topic

    • Award 1 mark for the correct evaluation of an expression involving MOD, ensuring the result is the remainder.
    • Award 1 mark for correct integer truncation when applying the DIV operator, distinct from real division.
    • Credit responses that correctly apply operator precedence (BIDMAS) to evaluate complex arithmetic expressions.
    • Award marks for accurate variable updates in a trace table following arithmetic assignment statements.

    Marking Points

    Key points examiners look for in your answers

    • Award 1 mark for the correct evaluation of an expression involving MOD, ensuring the result is the remainder.
    • Award 1 mark for correct integer truncation when applying the DIV operator, distinct from real division.
    • Credit responses that correctly apply operator precedence (BIDMAS) to evaluate complex arithmetic expressions.
    • Award marks for accurate variable updates in a trace table following arithmetic assignment statements.

    Examiner Tips

    Expert advice for maximising your marks

    • 💡In AQA Pseudocode, always use the keywords DIV and MOD explicitly; avoid symbols like % or // unless the question specifies a particular high-level language.
    • 💡When tracing algorithms, perform calculations for DIV and MOD on the side to ensure you are writing the strict integer result in the trace table.
    • 💡Check the data type of the variable receiving the result; assigning a real division result to an integer variable may require explicit casting or rounding logic.

    Common Mistakes

    Pitfalls to avoid in your exam answers

    • Confusing real division (/) with integer division (DIV), providing a decimal result (e.g., 2.5) where an integer (e.g., 2) is required.
    • Misinterpreting the MOD operator, often calculating the quotient or a decimal fraction rather than the integer remainder.
    • Failing to apply the correct order of operations, particularly when arithmetic operators are mixed with comparison or boolean operators.

    Key Terminology

    Essential terms to know

    Likely Command Words

    How questions on this topic are typically asked

    Calculate
    Trace
    Complete
    Write
    Determine

    Practical Links

    Related required practicals

    • •{"code":"Programming Skill","title":"Data Processing","relevance":"Using arithmetic to manipulate numerical data within variables."}

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