點樣大聲講解一個計算,而唔會聽落似部計數機
有個學生喺幫個朋友補習。個朋友問:「If a coat costs forty dollars and there's a twenty-five percent discount, what's the price?」個學生知道答案係三十蚊。佢衝口而出:「Forty times zero point seven five equals thirty。」個朋友有禮貌噉點吓頭,但一面茫然。數學係啱嘅,但個 故事 唔見咗。大聲講一個計算,同解出佢唔係同一回事。佢係關於帶人睇晒啲步驟,等佢哋跟到上,就好似喺一條熟悉嘅街上面指路噉。
點解呢樣嘢重要
你會比你諗嘅更頻密噉解釋計算 —— 喺公司傾預算嗰陣、喺堂上對功課嗰陣、喺會議描述圖表嗰陣、喺見工帶人睇個案研究嗰陣,或者喺口語考試嘅整合題目叫你總結數據嗰陣。好多學英文嘅人喺呢一刻會卡住,因為佢哋淨係識點 做 數學,唔識點 敘述 佢。Native speaker 用一小套指引字眼 —— first、then、next、which gives us、so、that comes out to —— 將一條方程式變成一個故事。一旦你識咗呢套工具,你就可以從容噉講解差唔多任何計算。
呢個同 點樣講小數、分數同比例而唔會卡住 自然噉配埋一齊,因為你一開始敘述數學,你就要用啱嘅方法讀出小數同分數。
規律
一個口語計算有三個部分:setup(設定)、steps(步驟)同 result(結果)。
Setup 引入個問題。
- 「Let's say the coat costs forty dollars。」
- 「Suppose the population is two hundred thousand。」
- 「Imagine you have a budget of five thousand。」
- 「Take a sales total of one hundred thousand。」
Steps 一件一件噉帶過啲數學。
- 「First, I take twenty-five percent of forty, which is ten。」
- 「Then, I subtract that from forty。」
- 「Next, I multiply by the number of months。」
- 「After that, I divide by twelve to get the monthly figure。」
- 「Now I add the tax。」
Result 有信心噉落到個答案。
- 「That gives us thirty dollars。」
- 「That comes out to about eight percent。」
- 「Which works out to roughly fifteen hundred。」
- 「So the answer is seventy-five。」
- 「And there you have it — thirty dollars。」
英文嘅運算字眼好短,而你應該好似真正嘅字噉講佢哋,唔好當作符號。
- Plus 或者 add 代表 +
- Minus 或者 subtract 代表 −
- Times、multiplied by,或者淨係 by 代表 ×
- Divided by 或者 over 代表 ÷
- Equals、is、gives,或者 comes out to 代表 =
- Squared 代表 ²、cubed 代表 ³、to the power of 代表更高次方
- Out of 代表分數,例如 18 out of 30
- To 代表比例,例如 3 to 1
- Percent of 代表 20% of 50
你亦可以用 basically、the way I'd do this,或者 here's the trick 嚟預先宣告結構。聽嘅人鍾意呢啲,因為佢哋示意「跟住我,唔會痛嘅」。
錯誤 / 自然 / 點解
| 錯誤 | 自然 | 點解 |
|---|---|---|
| Forty times zero point seven five equals thirty. | First, I take 25 percent of 40, which is 10. Then I subtract that from 40, so the answer is 30. | 第一個版本點出數學但唔點出步驟;第二個解釋咗邏輯。 |
| First I do calculation, then I divide. | First I work out the gross figure, then I divide by twelve. | 英文用 work out 或者 calculate 做動詞;do calculation 聽落唔自然。 |
| Twenty over hundred is point two. | Twenty divided by one hundred is zero point two. | Over 喺某啲語境用得,但敘述嗰陣 divided by 更清晰。 |
| 40 times 0.75 give us 30. | 40 times 0.75 gives us 30. | Gives 配單數主語要加 -s。 |
| That's coming out to 30. | That comes out to 30. | 固定短語係 that comes out to,簡單現在時,唔係進行時。 |
| First, second, third, I have the result. | First, then, finally, I have the result. | 英文步驟通常係 first / then / next / finally,口語數學唔用 first / second / third。 |
| Three power of two is nine. | Three to the power of two is nine. (or three squared) | 固定形式係 to the power of。 |
| Twenty out from thirty | Twenty out of thirty | 分數用 out of,唔係 out from。 |
| Take the half from the total. | Take half of the total. (or subtract half from the total) | Take the half from 混埋咗兩個結構。 |
常見情境
一個簡單折扣。「Let's say the jacket is one hundred dollars and the discount is twenty percent. First, I work out twenty percent of one hundred, which is twenty. Then I subtract that from one hundred, so the price comes out to eighty dollars。」留意講者點樣從來唔係淨係宣告「the answer is eighty」。佢哋一步步砌上去。
夾單。「Take the total of one hundred and twenty dollars. Divide that by four people, which gives us thirty each. If we want to add tip, say fifteen percent, that's eighteen on top, so each person owes about thirty-four fifty。」講者用 which gives us、say 同 so 將運算串連埋。每一步都有指引。
一個百分比增長。「Imagine your salary was sixty thousand and you got a ten percent raise. First, ten percent of sixty thousand is six thousand. Then you add that to the original, and there you have it — sixty-six thousand。」呢個係 increase by 結構嘅口語形式。
一個班嘅加權平均。「The way I'd do this is: take her midterm score, multiply it by point four, then take her final, multiply by point six, and finally add them together. So, eighty times point four is thirty-two, ninety times point six is fifty-four, which adds up to eighty-six。」聽嘅人跟到啲數學,就算佢哋自己唔識做。
估燃油費。「Suppose the trip is three hundred miles and the car gets thirty miles per gallon. First, divide three hundred by thirty, which is ten gallons. At four dollars a gallon, that comes out to forty dollars for the trip。」留意講者點樣用 at 嚟引入單位價錢 —— 一個常見嘅口語手法。
喺簡報描述圖表。「If you look at the second quarter, revenue rose from two million to two point four million. That's an increase of four hundred thousand, or roughly twenty percent. So we're up year-over-year by about a fifth。」簡報者喺圖表之上加埋粗略嘅數學,並帶聽眾睇晒個含義。
常犯嘅錯誤
- 將方程式當作原始符號噉讀:「Forty times zero point seven five equals thirty」,冇 setup 又冇指引。加上 first、then,同埋簡短解釋你做緊乜。
- 跳過咗 setup。聽嘅人要知啲數字代表乜。Let's say、suppose 或者 imagine 畀佢哋一個框架。
- 唔記得落個結果。做完晒啲步驟之後,用 that gives us、which comes out to 或者 so the answer is 嚟收尾。冇個收尾,聽嘅人就會吊喺半空。
- 將小數當作砌埋嘅數字噉讀(「zero point seventy-five」而唔係「zero point seven five」)。小數係喺 point 之後逐個數字噉讀。
- 喺數學用咗 do:do the multiplication、do the calculation。揀 work out、calculate、figure out,或者淨係嗰個運算本身:multiply、divide。
- 混淆 out of 同 out from。正確形式係 18 out of 30。
- 動詞需要 -s 嗰陣講咗 give us:係 which gives us,唔係 which give us。
- 濫用 so 呢個字。佢做指引好好用,但如果每一個分句都以 so 開頭,段說話就會聽落重複。同 which、then、and 溝埋用。
- 喺一個結果尾跳過咗單位。「Thirty」聽落空蕩蕩;「thirty dollars」或者「thirty percent」就話畀聽嘅人知係邊種答案。
迷你練習
大聲講解每個計算,用 setup + 步驟語言 + 一個最終結果短語。
- A laptop costs $1,200 with a 15% discount. What is the final price?
- A class has 40 students. 30% are absent. How many are present?
- Sales were $5,000 in Q1 and rose by 20% in Q2. What was the Q2 total?
- You drive 240 miles in 4 hours. What is the average speed?
- A recipe makes 24 cookies. You want to make a third of that batch. How many cookies?
總結
大聲講解一個計算,一半係數學,一半係講故事。Set up 個問題(「Let's say…」),用 first、then、next、which gives us walk through 啲步驟,用 so the answer is 或者 that comes out to land 個結果。用自然嘅運算字眼 —— plus、times、divided by、out of —— 並好似導遊噉指引。一旦呢啲短語變得自動自覺,你就可以從容噉敘述任何計算,就算喺考試、喺會議,甚至喺晚宴上有人即場叫你夾單都得。
想喺真實嘅試題句子入面練習數字、量詞同單位?喺 ExamRift 開始練習。