Master the Cambridge IGCSE Computer Science (0478) syllabus with examiner-verified advice on binary arithmetic, precise register definitions, Paper 2 algorithm construction, and scoring full marks in the 15-mark scenario-based pseudocode.
読了時間 5 分更新日: 2026年6月21日
試験の概要
試験数
2
満点
150
制限時間
3時間 30分
出題形式
4
試験
時間
配点
問題数
配点比率
出題形式
Paper 1 Computer Systems
1時間 45分
75
27
50%
Short Answer, Structured/Explain, Calculations / Tables
A silent scientific calculator may be used on papers where calculators are permitted (some papers are non-calculator). It must not be graphical or programmable and must hold no stored information.
AO1: AO1: Recall, select and communicate knowledge and understanding of computer science principles and concepts (40%)
AO2: AO2: Apply knowledge and understanding of computer science principles and concepts to a given context, including the analysis and design of computational or programming problems (40%)
AO3: AO3: Provide solutions to problems by evaluating computer systems, making reasoned judgements and presenting conclusions (20%)
過去問と採点基準にもとづいて作成（2023–2025）。
電卓プログラム
Table mode for roots & turning points
Scientific calculator (e.g. Casio fx-991 series)
目的: Tabulate \(y\) across a range of \(x\) to locate sign changes (roots) and approximate maxima/minima.
使う場面: Solving or sketching a function when you want to find where its graph crosses or turns.
手順
Enter the function in TABLE mode, set the start, end and step, then read where the sign of \(y\) changes or where it peaks.
試験での注意: Allowed on papers where a calculator is permitted; use a silent scientific calculator with no stored content and show your method.
Statistics mode (mean, SD & regression)
Scientific calculator (e.g. Casio fx-991 series)
目的: Read the mean \(\bar{x}\) and standard deviation directly, and the gradient/intercept (and \(r\)) of a linear regression for bivariate data.
使う場面: Any data-handling, statistics, or required-practical analysis question.
手順
Enter the data in STAT mode (1-VAR or A+BX), then recall \(\bar{x}\), \(\sigma\) or the regression coefficients.
試験での注意: Allowed on papers where a calculator is permitted; use a silent scientific calculator with no stored content and show your method.
Carry exact values with Ans & memory
Scientific calculator (e.g. Casio fx-991 series)
目的: Keep full-precision intermediate values to avoid rounding errors.
使う場面: Multi-step calculations where premature rounding loses the final accuracy mark.
手順
Use Ans, STO/RCL or the M+ memory to reuse the unrounded result of each step; round only the final answer.
試験での注意: Allowed on papers where a calculator is permitted; use a silent scientific calculator with no stored content and show your method.
Equation solver — to CHECK your working
Scientific calculator (e.g. Casio fx-991 series)
目的: Use the built-in EQN/SOLVE mode to verify roots of quadratics or simultaneous equations you have already solved by algebra.
使う場面: As a check only, after solving by hand.
手順
Enter the coefficients in EQN mode (or use SOLVE) and confirm they match your worked solution.
試験での注意: Allowed on papers where a calculator is permitted; use a silent scientific calculator with no stored content and show your method.
よくあるミス
1high影響する配点: 4Number systems
Converting binary operands to denary first, performing the addition in denary, and converting the sum back to binary.
回避方法: Always perform the binary addition column-by-column directly in binary. Ensure you write down explicit carry bits (e.g., 1s carried to the next left column) on the paper to secure working and method marks.
2high影響する配点: 3Algorithm design and problem-solving
Confusing validation with verification during database or user input scenarios.
回避方法: Remember that validation is an automated, rules-based computer system check (e.g., range check, type check). Verification is checking that data matches its original source, done via double-entry or manual visual checks by human users.
3medium影響する配点: 1File handling
Omitting the CLOSEFILE statement after executing operations in file-handling tasks.
回避方法: Always match every open file procedure with a corresponding CLOSEFILE command before completing your algorithm or subroutine.
4high影響する配点: 1Computer architecture
Writing generic, simple summaries for CPU performance terms, like defining clock speed strictly as 'how fast the CPU runs'.
回避方法: Use precise definitions: Clock speed is the number of cycles or instructions processed per second by the CPU, measured in Hertz (Hz) or Gigahertz (GHz).
5high影響する配点: 2Programming concepts
Omitting explanatory comments in the 15-mark scenario-based pseudocode question in Paper 2.
回避方法: Use double slashes (//) to add brief comments explaining loops, variable tracking, and output tasks. Up to 2 of the structure marks in the level-of-response grid are reserved specifically for code commentary.
6medium影響する配点: 1Types of software and interrupts
Using brand names (e.g., Windows, Excel, WinRAR, Photoshop) instead of generic terms.
回避方法: Never use commercial brand names in explanations of software categories. Use generic classifications like 'operating systems', 'spreadsheet applications', 'compression software', or 'image editors'.