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.
閱讀時間 5 分鐘更新於: 2026年6月21日
試卷概覽
卷數
2
總分
150
考試時間
3小時 30分鐘
題型
4
試卷
時間
分數
題數
比重
題型
Paper 1 Computer Systems
1小時 45分鐘
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%)
根據歷屆試題與評分準則整理（2023–2025）。
計算機程式
Table mode for roots & turning points
Scientific calculator (e.g. Casio fx-991 series)
用途: Tabulate \(y\) across a range of \(x\) to locate sign changes (roots) and approximate maxima/minima.
使用時機: Solving or sketching a function when you want to find where its graph crosses or turns.
步驟
Enter the function in TABLE mode, set the start, end and step, then read where the sign of \(y\) changes or where it peaks.
考試提示: 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)
用途: Read the mean \(\bar{x}\) and standard deviation directly, and the gradient/intercept (and \(r\)) of a linear regression for bivariate data.
使用時機: Any data-handling, statistics, or required-practical analysis question.
步驟
Enter the data in STAT mode (1-VAR or A+BX), then recall \(\bar{x}\), \(\sigma\) or the regression coefficients.
考試提示: 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)
用途: Keep full-precision intermediate values to avoid rounding errors.
使用時機: Multi-step calculations where premature rounding loses the final accuracy mark.
步驟
Use Ans, STO/RCL or the M+ memory to reuse the unrounded result of each step; round only the final answer.
考試提示: 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)
用途: Use the built-in EQN/SOLVE mode to verify roots of quadratics or simultaneous equations you have already solved by algebra.
使用時機: As a check only, after solving by hand.
步驟
Enter the coefficients in EQN mode (or use SOLVE) and confirm they match your worked solution.
考試提示: Allowed on papers where a calculator is permitted; use a silent scientific calculator with no stored content and show your method.
常見錯誤
1high涉及分數: 4Number systems
Converting binary operands to denary first, performing the addition in denary, and converting the sum back to binary.
如何避免: 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涉及分數: 3Algorithm design and problem-solving
Confusing validation with verification during database or user input scenarios.
如何避免: 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涉及分數: 1File handling
Omitting the CLOSEFILE statement after executing operations in file-handling tasks.
如何避免: Always match every open file procedure with a corresponding CLOSEFILE command before completing your algorithm or subroutine.
4high涉及分數: 1Computer architecture
Writing generic, simple summaries for CPU performance terms, like defining clock speed strictly as 'how fast the CPU runs'.
如何避免: 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涉及分數: 2Programming concepts
Omitting explanatory comments in the 15-mark scenario-based pseudocode question in Paper 2.
如何避免: 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涉及分數: 1Types of software and interrupts
Using brand names (e.g., Windows, Excel, WinRAR, Photoshop) instead of generic terms.
如何避免: Never use commercial brand names in explanations of software categories. Use generic classifications like 'operating systems', 'spreadsheet applications', 'compression software', or 'image editors'.