+ 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 approximately equal to 约等于 ≈ is approximately equal to 约等于号 < is less than 小于号 > is more than 大于号 ≤ is less than or equal to 小于或等于 ≥ is more than or equal to 大于或等于 % per cent 百分之… ∞ infinity 无限大号 √ (square) root 平方根 X squared X的平方 X cubed X的立方 ∵ since; because 因为 ∴ hence 所以 ∠ angle 角 ⌒ semicircle 半圆 ⊙ circle 圆 ○ circumference 圆周 △ triangle 三角形 ⊥ perpendicular to 垂直于 ∪ intersection of 并,合集 ∩ union of 交,通集 ∫ the integral of …的积分 ∑ (sigma) summation of 总和 ° degree 度 ′ minute 分 〃 second 秒 # number …号 @ at 单价