| | | |  |
一次我小孩做Beestar網上數學練習,一道很簡單的題卻丟了兩分. 仔細看後我認定是Beestar的答案不對.為了小孩這星期能上光榮榜, 我開始和Beestar 辯論. 那個題目大致是這樣的:
Casey’s family visited the Franklin Park Zoo. An 18-foot giraffe therewas the tallest animal they saw. Casey was 4.5 feet tall. How manytimes taller was the giraffe than Casey?
四個選擇是: A. 3, B. 4, C. 5, and D. 6
顯然18除以4.5等於4, 長頸鹿是凱西的4 倍, 就是說長頸鹿比凱西高三倍. 我小孩照我以前講的這個道理選的是A(3倍). 但Beestar的標準答案卻是B(4倍).
在國內小學時, 區分"是多少倍"和"多多少倍"是反複強調練習過的基本功. 長頸鹿的高度是凱西的4 倍, 就是長頸鹿比凱西高三倍.如果說長頸鹿比凱西高四倍,那長頸鹿就得是凱西的五倍了(4.5*5=22.5 feet)... 我據此概念和邏輯向Beestar陳述,Beestar 一開始還耐心地解釋, 後來雙方越說越費勁,他們把我搞糊塗了, 我也似乎讓他們感到莫名其妙.
最後我明白了,這是中文和英文語言上的差別. 在英文裏"是多少倍"和"多多少倍"竟然是一樣的,沒有區別!! 我至今對此感到奇怪和別扭. 照此說法,如果我和你一樣高, 難道用英文可以說我比你高一倍嗎?實在是不符合邏輯. 我問過不少老中家長,都有同感.
但Beestar 的解釋是這樣的:
"Taller than" indicates height is the quantity of interest, and thatthe giraffe's height is greater. "The giraffe is 4 times taller thanCasey" then becomes "The giraffe's height is four times Casey'sheight", i.e. H(g) = 4*H(c)...
In your reasoning, "taller than" implies that the quantity of interestis the subtractive difference, and not the ratio of the two heights.
As with most utterances, the meaning is mostly determined byconventions among the target audience (educated speakers), and not purelogic (which is ambiguous in this case).
Your argument is considered wrong by most experts, though yourexplanation might be supported by a small percentage of linguisticpreivists and pedants.
不管我對此解釋能否接受,我必需接受一個現實,上麵這道題隻有選B(4倍)才得分.在美國中小學數學考試中都會如此.所以自己輔導小孩數學的中國家長要當心,別不小心給孩子灌輸了錯誤的概念. 我後來發現這個問題僅限於中國家長.那些隻在美國學校學習的學生從不知道有這回事. 我問過一個父母從不管的ABC高中生, 她覺得我的問題很weird and funny.
雖然我小孩那次沒上光榮榜,發現這個問題也算是收獲不小.
| | | |
| | |
