underline 此外，提供一些有用的符号名称给你，以后说不定有用。+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≮...
