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.
อ่าน 5 นาทีอัปเดตเมื่อ: 21 มิ.ย. 2569
ภาพรวมข้อสอบ
จำนวนฉบับ
2
คะแนนเต็ม
150
เวลาสอบ
3ชม. 30นาที
ประเภทคำถาม
4
ฉบับ
เวลา
คะแนน
จำนวนข้อ
น้ำหนักคะแนน
ประเภทคำถาม
Paper 1 Computer Systems
1ชม. 45นาที
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%)
วัตถุประสงค์: Tabulate \(y\) across a range of \(x\) to locate sign changes (roots) and approximate maxima/minima.
ใช้เมื่อใด: Solving or sketching a function when you want to find where its graph crosses or turns.
ขั้นตอน
Enter the function in TABLE mode, set the start, end and step, then read where the sign of \(y\) changes or where it peaks.
ข้อควรระวังในการสอบ: 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)
วัตถุประสงค์: Read the mean \(\bar{x}\) and standard deviation directly, and the gradient/intercept (and \(r\)) of a linear regression for bivariate data.
ใช้เมื่อใด: Any data-handling, statistics, or required-practical analysis question.
ขั้นตอน
Enter the data in STAT mode (1-VAR or A+BX), then recall \(\bar{x}\), \(\sigma\) or the regression coefficients.
ข้อควรระวังในการสอบ: 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)
วัตถุประสงค์: Keep full-precision intermediate values to avoid rounding errors.
ใช้เมื่อใด: Multi-step calculations where premature rounding loses the final accuracy mark.
ขั้นตอน
Use Ans, STO/RCL or the M+ memory to reuse the unrounded result of each step; round only the final answer.
ข้อควรระวังในการสอบ: 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)
วัตถุประสงค์: Use the built-in EQN/SOLVE mode to verify roots of quadratics or simultaneous equations you have already solved by algebra.
ใช้เมื่อใด: As a check only, after solving by hand.
ขั้นตอน
Enter the coefficients in EQN mode (or use SOLVE) and confirm they match your worked solution.
ข้อควรระวังในการสอบ: Allowed on papers where a calculator is permitted; use a silent scientific calculator with no stored content and show your method.
ข้อผิดพลาดที่พบบ่อย
1highคะแนนที่เกี่ยวข้อง: 4Number systems
Converting binary operands to denary first, performing the addition in denary, and converting the sum back to binary.
วิธีหลีกเลี่ยง: 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.
2highคะแนนที่เกี่ยวข้อง: 3Algorithm design and problem-solving
Confusing validation with verification during database or user input scenarios.
วิธีหลีกเลี่ยง: 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.
3mediumคะแนนที่เกี่ยวข้อง: 1File handling
Omitting the CLOSEFILE statement after executing operations in file-handling tasks.
วิธีหลีกเลี่ยง: Always match every open file procedure with a corresponding CLOSEFILE command before completing your algorithm or subroutine.
4highคะแนนที่เกี่ยวข้อง: 1Computer architecture
Writing generic, simple summaries for CPU performance terms, like defining clock speed strictly as 'how fast the CPU runs'.
วิธีหลีกเลี่ยง: 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).
5highคะแนนที่เกี่ยวข้อง: 2Programming concepts
Omitting explanatory comments in the 15-mark scenario-based pseudocode question in Paper 2.
วิธีหลีกเลี่ยง: 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.
6mediumคะแนนที่เกี่ยวข้อง: 1Types of software and interrupts
Using brand names (e.g., Windows, Excel, WinRAR, Photoshop) instead of generic terms.
วิธีหลีกเลี่ยง: Never use commercial brand names in explanations of software categories. Use generic classifications like 'operating systems', 'spreadsheet applications', 'compression software', or 'image editors'.