A comprehensive, examiner-designed preparation package for Cambridge IGCSE Co-ordinated Sciences (Double Award) 0654. This package includes a detailed breakdown of all papers, an exhaustive exam-tips study guide written by an expert tutor, a list of high-priority student mistakes from recent exam cycles, and a step-by-step scientific calculator methodology to maximize raw marks across the Biology, Chemistry, and Physics components.
阅读时间 4 分钟更新于: 2026年6月21日
试卷概览
卷数
3
总分
220
考试时间
4小时 15分钟
题型
3
试卷
时间
分数
题数
比重
题型
Paper 2 Multiple Choice (Extended)
45分钟
40
—
—
—
Paper 4 Theory (Extended)
2小时
120
—
—
—
Paper 6 Alternative to Practical
1小时 30分钟
60
—
—
—
评级
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计算器规定
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: Knowledge with understanding (50%)
AO2: AO2: Handling information and problem-solving (30%)
AO3: AO3: Experimental skills and investigations (20%)
根据历届试题与评分标准整理（2023–2025）。
计算器程序
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.
使用时机: Solving or sketching a function when you want to find where its graph crosses or turns.
步骤
Enter the function in TABLE mode, set the start, end and step, then read where the sign of \(y\) changes or where it peaks.
考试提示: 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.
使用时机: Any data-handling, statistics, or required-practical analysis question.
步骤
Enter the data in STAT mode (1-VAR or A+BX), then recall \(\bar{x}\), \(\sigma\) or the regression coefficients.
考试提示: 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.
使用时机: Multi-step calculations where premature rounding loses the final accuracy mark.
步骤
Use Ans, STO/RCL or the M+ memory to reuse the unrounded result of each step; round only the final answer.
考试提示: 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.
使用时机: As a check only, after solving by hand.
步骤
Enter the coefficients in EQN mode (or use SOLVE) and confirm they match your worked solution.
考试提示: Allowed on papers where a calculator is permitted; use a silent scientific calculator with no stored content and show your method.
常见错误
1high涉及分数: 2Motion, forces and energy
Failing to convert metric units before substituting values into calculations, particularly with moments (using cm instead of m) and wave equations (using MHz instead of Hz).
如何避免: Build a checklist step: read the question, highlight standard SI units, execute calculations (e.g., dividing cm by 100 to get meters) *before* substituting into equations.
2high涉及分数: 1Coordination and response
Using general, non-scientific terminology instead of specific required vocabulary (such as writing 'blood vessels expand' instead of 'arterioles dilate' for vasodilation).
如何避免: Study official physiological descriptions. Explicitly use 'arterioles dilate' and 'capillaries' when explaining thermoregulation in the skin.
3medium涉及分数: 2Organic chemistry
Omitting the production of water in the description of condensation polymerisation of nylon from dicarboxylic acid and diamine.
如何避免: Remember that condensation polymerisation *always* produces a small molecule (usually water or hydrogen chloride) in addition to the polymer chain.
4high涉及分数: 1Chemical energetics
Drawing energy profile change arrows that stretch to the peak of the curve rather than exactly representing the enthalpy change distance from reactants to products.
如何避免: Verify that your activation energy (Ea) arrow starts at the reactants and goes to the peak, whereas the enthalpy change (delta H) arrow connects the level of reactants to products exactly.
5medium涉及分数: 2Waves
Misinterpreting the two-way travel of ultrasound waves, failing to divide the total echo time by 2, leading to doubled distance values.
如何避免: When a sound or ultrasound wave travels to a boundary and bounces back, always halve either the total time or the final computed distance value (\( d = \frac{v \times t}{2} \)).
6high涉及分数: 3Experimental techniques and chemical analysis
Drawing sketchy, multi-lined biological drawings rather than clear, continuous outlines in Paper 5/6.
如何避免: Use a sharp HB pencil to make a single, sweeping continuous line outline. Do not shade or add artistic cross-hatching to biological sketches.
7high涉及分数: 1Chemical reactions
Using imprecise words like 'more collisions' rather than 'more frequent collisions' in rate-of-reaction explanations.
如何避免: Always refer to rate. Use the specific phrasing 'collisions per unit time' or 'more frequent successful collisions' to secure full marks.
8medium涉及分数: 1Reproduction
Confusing mitosis and meiosis when discussing the division of a zygote or gamete production.
如何避免: Remember: Mitosis creates genetically identical cells for growth and repair. Meiosis produces genetically diverse haploid gametes (sperm and egg).