Edit
The expression of symbols in English
+ plus 加;正- minus 减;负± plus-minus 正负* is multiplied by / multipication sign 乘÷ is divided by / division sign 除= is equal to 等于≠ is not equal to 不等于≡ or === is equivalent to 全等于/恒等于? is approximately equal to or equal to / almost equal or equal to 等于或约等于≈ is approximately equal to / almost equal to 约等于< is less than 小于> is greater than 大于≮ is not less than 不小于≯ is not greater than 不大于≤ is less than or equal to 小于或等于≥ is greater than or equal to 大于或等于% percent / per cent 百分之…‰ per mille 千分之…? per ten thousand 万分之…∞ infinity ∝ varies as / proportional to 与...成比例√ square root 平凡根? cube root∴ hence / therefor 所以 ∵ since / because 因为∶ ratio 比率;比例∷ equals / proportion 成比例∠ angle 角⌒ semicircle 半圆⊙ circle 圆○ circumference 圆周△ triangle 三角形⊥ perpendicular to 垂直于∪ union of 并,合集∩ intersection of 交,通集∫ the integral of …的积分∑ (sigma) summation of 总和° degree 度′ minute 分″ second 秒# number …号℃ Celsius system 摄氏度@ at 在
Reference:
51Talk worry-free English/mac simplified Pinyin Input method
(Punctuation/math/...) English/English Expressions of symbols