< is less than 小于号
> is greater than 大于号
= is equal to 等于号
+ plus 加号；正号
- minus 减号；负号
± plus or minus 正负号
× is multiplied by 乘号
÷ is divided by 除号
≠ is not equal to 不等号
≡ is equivalent to 全等于号
≤ is not less than 小于等于号
≥ is not more than 大于等于号
≢is less than or equal to 小于或等于号
≣ is more than or equal to 大于或等于号
% per cent 百分之…
‰ per mill 千分之…
∞ infinity 无限大号
○ circumference 圆周 π pi 圆周率
△ triangle 三角形
∑ (sigma) summation of 总和 ° degree 度 ′ minute 分 ″ second 秒
℃ Celsius system 摄氏度