＋

plus ;positive

－

minus ;negative

×

multiplied by ;times

÷

divided by

＝

equals

≈

approximately equals

≠

not equal to

＜

less than

＞

greater than

≤

equal to or less than

≥

equal to or greater than o

( )

round brackets ;parentheses

[ ]

square brackets

{ }

braces

∈

is a member of the set

⊂

is a subset of

∽

similar to

≌

congruent to

*

denotes an operation

∴

therore

∵

because

∶

ratio sign, divided by, is to

∷

equals, as(proportion)

square root of

cube root of

∥

parallel to

⊥

perpendicular to, at right angles with

∠

angle

∟

right angle

º

degree

′

minute

″

second

⊙

circle

A⁀B

arc AB

e

the base of natural logarithms,approx.2.71828

x!

factorial x, x(x-1)(x-2)---1

log_nx

log x to the base n

π

pi

lnx

log x to the base e(natural logarithm)

lgx

log x to the base 10(common logarithm)

|x|

the absolute value of x