常用数学符号及数学表达式的读法

常用数学符号及数学表达式的读法

Item Read as

1/2 A half / one half

1/3 A third / one third

2/3 Two thirds

1/4 A quarter / one quarter / a fourth / one fourth

1/10 A tenth / one tenth

1/100 A [one] hundredth

1/1000 A [one] thousandth

1/1234 One over a thousand two hundred and thirty-four

3/4 Three fourths / three quarters

4/5 Four fifths / four over five

113/300 One hundred and thirteen over three hundred

2½Two and a half

7

Two and seven over eight / two and seven eighths

2

8

1

Three and one eighth

3

8

1

Four and a third

4

3

125 A [one] hundred twenty-five and three fourths [quarters] 3

4

0.1 [ .1] Zero point one / nought point one

0.01 [.01] Zero point zero one / nought point nough one

0.25 [.25] Nought point two five

0.045 Decimal [point] nought four five

2.35 Two point three five

Four point nine recurring

49.

Three point nought three two six, two six recurring

30326

.

45.67 Four five [forty-five] point six seven

38.72 Three eight point seven two / thirty-eight decimal seven two

+ Plus ; positive

- Minus; negative

±Plus or minus

×[•] Multiplied by / times

÷Divided by

= Is equal to / equals

≡Is identically equal to

≈≒≌

Is approximately equal to / approximately equals ∵

Because ∴

therefore →

Maps into π

pi ∑

Sigma / summation of x n The n th power of x / x to the power n

log n x Log x to the base n

10log x Log x to the base 10 / common logarithm log e x Log x to the base e / natural logarithm |x | The absolute value of x

x The mean value of x

b ’ b prime

b ’’ b double prime

b ’’’ b triple prime

b 1 b sub one

b m b sub m

x x dot

x x two dots

''m x b double prime sub m

()

y F x =

y is a function of x dy dx

The first derivative of y with respect to x 22d y d x

The second derivative of y with respect to x n n d y d x The n th derivative of y with respect to x

y x

∂∂ The partial derivative of y with respect to x , where y is a function of x and another variables ()F'x The first derivative of function F of x with respect to x

⎰

integral

b

a ⎰ Integral between limits a and b

F Vector F

x +y x plus y

a =

b a is equal to b / a equals to b / a is b a ≠b a is not equal to b / a is not b a ±b a plus or minus b

a ≈

b a is approximately equal to b a >b a is greater than b

a »

b a is much greater than b a< b a is less than b

a «

b a is much less than b

7+3 > 8 7 plus 3 is greater than 8 12 < 5+8 12 is less than 5 plus 8

a ⊥

b a is perpendicular to b

a //

b a is parallel to b

∠A Angle A

s=vt s equals v times t

s=v /t s equals v over t

1 :

2 The ratio of one to two

x 2 x square

y 3

y cube t V V a t -=

a equals V su

b t minus V over t