(急)专家老师:07年杭州市舟山市英语中考卷中的几个问题

(急)请问专家老师:07年杭州市,舟山市卷中的几个题 听力题:.......Imagine you wish to multiply 23 by 17. In Chinese, it means 23 乘以 17. Half of 23 is 11.5. Write only 11 under 23 as you see in the paper. Half of 11 is 5.5. Write only 5 under 11. Now think it over, what number will you write under 5? Yes, you are right, just 2. Now please write the number under 5. Continue until you have 1.



Now write numbers under 17. But this time you must multiply each number by two to write the number under it. For example, you should write 34 under 17. As a rule, what number will you write under 34? Yes, you are right, 68. Now please write the number under 34. Continue until you have a number on the same line as 1. Now draw a line through any row that has an even number on the left. Yes, even number means 偶数 in Chinese. In our example there is only one even number. Right? Now please draw a line through the line that has an even number on the left. Now add the rest of the numbers in the right-hand row. Believe it or not, you will get the right answer. What is it? OK. Please write the number, I mean the right answer in the right place. 这段文字我不太理解,请专家用一个图表(或算式)来帮我解释一下好吗?谢谢!

   

参考案 不翻译了，用自己的话说一遍。

要算23乘以17，就把这两个数字写在纸上。然后在左边不断除以2，只写整数部分，一直写到1.

然后在右边不断乘以2，写到和左边的行数一样（在这个例子里就是5行）。

找出左边是偶数的地方，把右边对应的数字划去（在这个例子里只有2－136这一行，所以划掉136）。

在右边，把没划掉的数字（17、34、68、272）加起来，就得到了391 － 23×17的案。

如下图。

23 17
11 34
5 68
2 (136)
1 272

272+68+34+17=391
23*17=391

不过。。。好无聊哦。。。