【DSE 數學計數機全攻略：選購及使用】DSE Maths Calculator Guide: Choosing and Using Your Calculator

SketchMath 數學團隊 SketchMath Maths Team ｜ 更新 Updated 2026-10-20

只可使用考評局認可名單上的計數機型號，並要核對你應考當年的名單。把計數機設為角度模式（DEG），並在考試前熟習方程、統計、列表、分數及記憶功能。計數機用來驗算，試卷仍要寫出步驟。Only use a calculator on the HKEAA list of approved models, and check the list for the year you sit the exam. Set it to degrees (DEG), and learn the equation, statistics, table, fraction and memory functions before exam day. The calculator checks your answer; the paper still needs the working.

用 AI 逐步解DSE 計數機全攻略題目 Solve it with AI

值得熟習的功能 Functions Worth Learning

角度模式Angle modeDSE 三角學用角度（DEG）；模式錯誤便會算錯Degrees (DEG) for DSE trigonometry; a wrong mode gives wrong values
方程模式Equation mode可解二次、三次方程及二元、三元聯立方程Solves quadratics, cubics and 2- or 3-unknown simultaneous equations
統計模式Statistics mode單變量數據：平均數、標準差（σ）、總和One-variable data: mean, standard deviation (σ), sums
列表／CALCTable / CALC快速把公式代入多個數值Evaluate a formula at many values quickly
分數及準確值Fraction and exact form在小數、分數及根式之間轉換Switch between decimals and fractions or surds
記憶Memory把中間答案存入記憶，不要重新輸入近似值Store intermediate answers instead of re-typing rounded ones
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DSE 計數機全攻略例題詳解 Worked Examples

例題 1 Example 1：驗算二次方程 Check a quadratic

用方程模式驗算 2x² − 5x − 3 = 0 的根。Use the equation mode to check the roots of 2x² − 5x − 3 = 0.

  1. 輸入係數 2, −5, −3Enter the coefficients 2, −5, −3
  2. 讀出兩個解並代入驗算Read the two solutions and confirm by substituting

答案： Answer: x = 3 or x = −1/2

例題 2 Example 2：標準差 Standard deviation

用統計模式求 4, 6, 8 的平均數及標準差（σ）。Use the statistics mode to find the mean and standard deviation (σ) of 4, 6, 8.

  1. mean = 6
  2. σ = √[(4 + 0 + 4) / 3] = √(8/3)

答案： Answer: σ ≈ 1.633

例題 3 Example 3：角度模式 Angle mode

為甚麼 sin 30 在一部計數機得 −0.988，在另一部卻得 0.5？Why does sin 30 give −0.988 on one calculator and 0.5 on another?

  1. 一部在弧度模式（30 弧度）；另一部在角度模式（30°）One is in radian mode (30 radians); the other is in degree mode (30°)

答案： Answer: DSE 三角學要轉用角度（DEG）。Switch to degrees (DEG) for DSE trigonometry.

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💡 應試陷阱與秘訣 Exam Traps & Secrets

⚠️ 只可使用認可型號，並帶備用品 Use only an approved model, and bring spares請核對你應考當年的考評局通告，並帶備用電池。現行名單請勿以本頁為準。Check the HKEAA notice for the year you sit the exam, and carry spare batteries. Do not rely on this page for the current list.
⚠️ 括號及近似 Brackets and rounding分子及分母要加括號，並把完整數值存在記憶中。中途近似會改變最後幾位數字。Use brackets for numerators and denominators, and keep full values in memory. Rounding in the middle changes the last digits.
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✏️ 自我測試：互動練習 Self-Test: Interactive Practice

溫習方法：點擊以下任何題目，即時在坐標網格載入並核對計算步驟。How to study: click any question to load it on the coordinate grid and check your steps.

(驗算 Check answers)示範怎樣用計數機驗算 x² − 6x + 5 = 0 及一對聯立方程。Show me how to check x² − 6x + 5 = 0 and a pair of simultaneous equations on my calculator.
(清單 Checklist)列出必修部分應該練習的計數機功能。List the calculator functions I should practise for the Compulsory Part.
(避免錯誤 Avoid errors)DSE 數學中有哪些計數機錯誤最容易失分？Which calculator mistakes cost marks in DSE Maths?
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常見問題 Frequently Asked Questions

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