2024年4月8日发(作者：)

U4 Numbers

Review of the text.

Numbers

Everyone’s language

How many languages do you know? Everyone knows (1) _________ ________ (至少)

two---his or her own language and the (2) ________ ________ ________. (国际化的数学语言)

Ancient numbers

(3) ________ ________ _________, (在古代) people wrote numbers (4) _________

_________ ________ ________, (用很多不同的方式) as these pictures of the number 6 show.

However, they nearly (几乎) all (5) __________ (计算) in the same way – (6) _________

_________. (十进制)

Zero

Most of us (7) ________ ________ _________ _________ _________ (使用的数字体系)

with numbers from 1 to 9 and zero. With these ten numbers, we can write any number (8)

_________ _________ _________ _________ ________ _________ . (从最大到最小)The

Indians first (9) _________ (创造) and (10) __________ (推进) the 1 to 9 system of numbers.

They then invented the zero. This was (11) __________ __________ ___________ __________

(一项非常重要的发明) because (12)

____________________________________________________________ (这使的书写大的数

字和计算会方便一些)

Calculating machines

(13) _______________________________________________. (最早的计算器之一是算盘)

(14) ____________________________________________________________________ (算盘用

起来是如此快而准确，所以人们至今仍然使用着)

(15) ______________________________ (现在化的电子计算器) can (16)

____________________________________________. (加减乘除) It can also calculate

percentages (百分数) and (17) _________ _________. (平方根)

Computers are very powerful calculating machines. (18) __________ __________

_________, (立即) a computer can do a calculation that you could not do (19)

______________________________. (一辈子的时间)

Brain against computer

Some people call the brain (20) __________ __________ __________. (活的电脑) Is a

human brain a (21) __________ __________(更强) calculator than a computer? The following

story may give an answer.

Shakuntala Devi is a lady from India with (22) ________ ________ ________. (惊人的大脑)

Shakuntala and a very powerful computer (23) ______________________________________.

(都要解决这个问题)

Shakuntala’s brain (24) _______________________________, (花了50秒给出答案) like

lightning. (像闪电一样) The computer took a minute. However, someone (25)

________________________, (先设计出相关的程序和指令) and that took many hours. No one

had to program Shakuntala!

Use your own living computer to solve the problem above. If it is not powerful enough, you

will find the answer on page 67.

【答案】 least ational language of numbers ancient times many different ways

d tens the system of numbers the biggest to the smallest ed

ped 11.a very important invention made it easier to write big numbers and to

calculate of the first calculating machines was an abacus es are so fast and

accurate that people still use them today. 15.A modern electronic calculator , subtract,

multiply and divide roots a flash your whole lifetime 20.a living computer

21. more powerful amazing brain given this problem to solve fifty seconds to

find the answer to first program the comp

语法：祈使句