【DSE 數學計數機記憶及 CALC 技巧】Calculator Memory and CALC Tricks for DSE Maths

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

三個習慣可節省時間及減少失分：把很長的答案存入記憶變數而不要重新輸入、在下一個計算重用上一個答案，以及用 CALC（或列表模式）把同一條公式代入多個數值。按鍵名稱因型號而異，請參考說明書。Three habits save time and marks: store a long answer in a memory variable instead of retyping it, reuse the last answer in the next calculation, and use CALC (or table mode) to evaluate one formula at several values. Key names differ between models, so check your manual.

用 AI 逐步解計數機記憶及 CALC 技巧題目 Solve it with AI

記憶習慣 Memory Habits

儲存Store把結果存入 A、B、C 等字母變數Save a result in a letter variable such as A, B or C
上一個答案Last answer用 Ans，避免近似誤差累積Use Ans so rounding errors do not build up
CALC輸入一次公式，再為每個未知數輸入新數值Type a formula once, then give it new values for each unknown
列表Table列出一段 x 範圍的 f(x)，以找根或轉折點List f(x) for a range of x to find roots or a turning point
重播Replay返回修改之前的算式，而不用重新輸入Scroll back to edit an earlier line instead of retyping it
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計數機記憶及 CALC 技巧例題詳解 Worked Examples

例題 1 Example 1：一次計出複利 Compound interest in one pass

求 8000 × 1.015⁸，準確至最接近的仙。Find 8000 × 1.015⁸ to the nearest cent.

  1. 計算 1.015⁸ = 1.12649… 並保留為 AnsCalculate 1.015⁸ = 1.12649… and keep it as Ans
  2. 計算 Ans × 8000，不用重新輸入近似值Multiply Ans × 8000 without retyping the rounded value

答案： Answer: $9011.94

例題 2 Example 2：用 CALC 測試因式 Test factors with CALC

用 CALC 找出 x = −1, 2, 3 中，哪些是 x³ − 4x² + x + 6 的根。Use CALC to find which of x = −1, 2, 3 are roots of x³ − 4x² + x + 6.

  1. 輸入多項式一次，再依次輸入 x = −1、2、3Enter the polynomial once, then give x = −1, 2, 3 in turn
  2. 三個結果都是 0All three results are 0

答案： Answer: 全部都是：x³ − 4x² + x + 6 = (x + 1)(x − 2)(x − 3)All three: x³ − 4x² + x + 6 = (x + 1)(x − 2)(x − 3)

例題 3 Example 3：準確的分數 Exact fraction

用計數機把 0.375 化為分數。Convert 0.375 to a fraction with the calculator.

  1. 使用小數與分數互換（S⇔D）鍵Use the decimal-to-fraction (S⇔D) key

答案： Answer: 3/8

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💡 應試陷阱與秘訣 Exam Traps & Secrets

⚠️ 記憶不是步驟 Memory is not working即使由計數機計算，也要在紙上寫出代入的式子或公式。分數是根據步驟給的。Show the substitution or formula on paper even if the calculator did the arithmetic. Marks follow the working.
⚠️ 新題目前要清除記憶 Clear stored values before a new question變數中遺留的舊數值可能混進下一個計算。重用字母前，要先清除記憶。A leftover value in a variable can sneak into the next calculation. Reset the memory between questions when you reuse letters.
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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.

(練習 Drill)給我一個 10 分鐘的練習，用代數題練習記憶、Ans 及 CALC。Give me a 10-minute drill that practises memory, Ans and CALC on algebra questions.
(二次方程 Quadratics)示範怎樣用記憶值快速驗算二次方程的根及判別式。Show how to check a quadratic root and a discriminant quickly with stored values.
(利息 Interest)列出三年複利題的計數機步驟。List the calculator steps for a 3-year compound interest question.
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常見問題 Frequently Asked Questions

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