GMAT中主要数学符号的英文表达：
+: plus
-: minus
*: 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
( ): round brackets; parentheses
[ ]: square brackets
{ }: braces
∈: is a member of the set
?: is a subset of
∽: similar to
≌: congruent to
*: denotes an operation
∴: therefore
∵: because
∶: ratio sign, divided by
∷: equals, as(proportion)
