+:plus(positive正的)
-：minus（negative负的）
*：multiplied by
÷：divided by
=:be equal to
≈:be approximately equal to
():round brackets(parenthess)
[]:square brackets
{}:braces
∵:because
∴:therefore
≤:less than or equal to
≥：greater than or equal to
∞：infinity
LOGnX:logx to the base n
xn:the nth power of x
f(x):the function of x
dx:diffrencial of x
x+y:x plus y
(a+b):bracket a plus b bracket closed
a≠b：a isn't equal to b
a>b:a is greater than b
a>>b:a is much greater than b
a≥b: a is greater than or equal to b
x→∞：x approches infinity
x2:x square
x3:x cube
√￣x:the square root of x
3√￣x:the cube root of x
3‰：three peimill
n∑i=1xi:the summation of x where x goes from 1to n
n∏i=1xi:the product of x sub i where igoes from 1to n
∫ab:integral betweens a and b
1. Cardinals and Ordinals 基数和序数
(1)100以内的数词
基数 序数
Roman Arabic
Numerals Numerals
罗马数字 阿拉伯数字 读法 数码 读法
I 1 one 1st the first
II 2 two 2nd the second
III 3 three 3rd the third
IV 4 four 4th the fourth
V 5 five 5th the fifth
VI 6 six 6th the sixth
VII 7 seven 7th the seventh
VIII 8 eight 8th the eighth
IX 9 nine 9th the ninth
X 10 ten 10th the tenth
XI 11 eleven 11th the eleventh
XII 12 twelve 12th the twelfth
XIII 13 thirteen 13th the thirteenth
XIV 14 fourteen 14th the fourteenth
XV 15 fifteen 15th the fifteenth
XVI 16 sixteen 16th the sixteenth
XVII 17 seventeen 17th the seventeenth
XVIII 18 eighteen 18th the eighteenth
XIX 19 nineteen 19th the nineteenth
XX 20 twenty 20th the twentieth
XXI 21 twenty-one 21st the twenty-first
XXV 25 twenty-five 25th the twenty-fifth
XXX 30 thirty 30th the thirtieth
XL 40 forty 40th the fortieth
L 50 fifty 50th the fiftieth
LX 60 sixty 60th the sixtieth
LXX 70 seventy 70th the seventieth
LXXX 80 eighty 80th the eightieth
XC 90 ninety 90th the ninetieth
IC 99 ninety-nine 99th the ninety-ninth
C 100 one hundred 100th the hundredth
CII 102 a hundred 102nd the (one) hundred
and two and second
246 two hundred and forty-six
751 seven hundred and fifty-one
发表于 2006-11-23 16:36:07