一道用英文短文叙述的数学题
一道用英文短文叙述的数学题
Now boys and girls,let's begin our class.As I know,you are interested in some strange math problems.So today I'm going to tell you one of the strangest ways to multiply numbers of two or more figures.Matbe you don't know the word“multiply”.The word “multiply”means “乘,乘法的乘”in Chinese.For example,8 multiplied by 2 is 16.It means “8乘以2是16”in Chinese.Do you understand now?Of course,there are many ways to multiply numbers.But here is one of the strangest.
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 on the paper.Half of 11 is 5.5.Write only 5 under 11.Now think it over,what number will you write under Contiune until you have 1.
Now write the number under 17.But this time you must mltiply each numbrt 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?Contiune 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 on the left.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 rightanswer.What is it?OK.Please write the number,I mean the right answer in the right place.
Now class,I'll give you several minutes to discuss how it works.
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‖ 23 × 17 ‖
‖ 11 34 ‖
‖ 5 ( ) ‖
‖ ( ) 136 ‖
‖ 1 272 ‖
‖— — — — — — ‖
‖ ( ) ‖
ˉˉˉˉˉˉˉˉˉˉˉˉˉˉˉˉˉ
What is the last number you should write?
391
请复制表格填上相应数字并结束391是怎么来的!
‖ 23 × 17 ‖
‖ 11 34 ‖
‖ 5 (68)‖
‖(2 ) 136 ‖
‖ 1 272 ‖
‖17+34+68+272=391‖
‖ (391 ) ‖
将左边那些对应右边不是偶数的数加起来就是所要答案.