+ 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 equal to 等于号≠ is not equal to 不等于号≡ is equivalent to 全等于号≌ is equal to or approximately equal to 等于或约等于号≈ is approximately equal to 约等于号< is less than 小于号> is more than 大于号≮ is not less than 不小于号≯ is not more than 不大于号≤ 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∝ varies as 与…成比例√ (square) root 平方根∵ since; because 因为∴ hence 所以∷ equals, as (p