unit 1 收得领地Day 1 牛刀小试计算类概述
虽然近五年来十次四级听力考试计算类的题型在小对话中出现的频率不高，但有可能这次你会遇见咯!所以不得不防之。相对其他题型而言，计算类是四级听力中的基础题(可分为计算题、细节辨认题、等值转换题)，也应该是你的抢分题，故不可大意失荆州。地球人都知道四级中听力的计算类不是在考咱们连小学生一年级都会做的加减乘除，测评大家的IQ，醉翁之意不在酒，而是在考大家对英语听力的反应速度，只要意识到这一点，现在你就要学会如何运用技巧来所谓的抓鱼了核心在于抓住关键的细节所在之处，in a other word，你要知道根据题意该听什么，怎么把它去听准。
计算题
M: When does the next shuttle bus leave?
W: You have just missed one by 20 minutes. We have a bus every 45 minutes, so youll have to wait for a while.
Q: How long does the man need to wait for the next bus?
A) 25 minutes B) 65 minutes
C) 20 minutes D) 45 minutes
【解析】 当你看见这四个选项，不难发现这一题是在考与时间有关的内容，并且从选项当中可以推测到是考时间的加减关系，因为其中三个选项都是正确答案的干扰选项，说到这里，你就要做好充分的思想准备。原文中除了听清20和45两个数字之外，重要的是明白其之间的联系，通过missed知道已经错过，而介词by专门用在计算题表差额;通过every知道每辆车之间45分钟，问的是wait for the next bus 还得等多长时间，很清楚这里是减法的计算关系，所以选择A。
细节辨认题
M: I wonder if Jack will come here by 11 oclock.
W: His wife said he left home at 10:30, so he should be here at 11:20 at the latest.
Q: What time did Jack leave home?
A) 11:20 B) 10:30 C) 10:50 D) 11:30
【解析】 原文中出现三个数字，11:00是Man觉得杰克应该到的时间;10:30是杰克的妻子说他离开家的时间;11:20是Woman认为杰克应该到的时间。我们再来看问题，选B是对号入座。
【死马活医】 如果没听清，这里就要充分运用技巧来猜选，时间中的B和C选项，可以合并小时10时间中的B和D选项，可以合并分钟30，通过合并同列项方法，就能猜选答案为B。
等值转换题
M: These postcards cost 60 cents a dozen.
W: Two dozen should certainly do.
Q: How many postcards will the man buy?
A) 60 B) 12 C) 24 D) 16
【解析】 第一句话是声东击西，60美分一打，问题并不是我们所期待的考多少钱，考价格，而是在问数量，第二句话提到数量，但前面加了pair,意味着要乘以2。除了清楚这些还不够，dozen是英语中数字的代用词，表示12。所以选C。
常见的数字计算类提问形式：
1. What time? 5. How far?
2. How much/many? 6. How often?
3. How long? 7. How old?
4. When?
先来热热身
1. A) 6 B) 15 C) 20 D) 21
2. A) 5:00 B) 5:15 C) 5:30 D) 5:45
3. A) $ 2 B) $ 20 C) $ 12 D) $ 10
4. A) 5:00 B) 5:15 C) 5:30 D) 5:45
5. A) in 5 minutes B) in 10 minutes
C) in 15 minutes D) in 25 minutes
1. 【选D】原文重现
M: Tom must be over twenty now.
W: I think so, when I left Paris six years ago, he was already fifteen.
Q: How old is Tom now?
2. 【选B】原文重现 1997.1
M: Whats the time for departure?
W: 5:30. That only leaves us 15 minutes to go through the customs and check our baggage.
Q: At what time did the conversation take place?
3. 【选C】原文重现
W: Good evening , sir. Why not try our dry beer. Two dollars for each bottle, and twenty for a dozen.
M: Well, a dozen is too much for me. Give me a half.
Q: How much does the man need to pay?
4. 【选C】原文重现
W: Its five already, I suppose the meeting will be postponed to 5:45.
M: Well, the secretary said something unexpected happened. The meeting will begin in 30 minutes.
Q: When will the meeting begin?
5. 【选D】原文重现
W: Excuse me, sir. Does the No.1 bus stop here?
M: Yes, but the bus only runs every half hour and one just went by five minutes ago.
Q: When will the No.1 bus come?