| Function func | Return value |
| abs | Absolute value of the argument arg （绝对值） |
| sign | Plus/minus sign of the argument arg: -1, if the value of arg is negative; 0 if the value of arg is 0; 1 if the value of arg is positive. （正负号） |
| ceil | Smallest integer number that is not smaller than the value of the argument arg.（向下取整） |
| floor | Largest integer number that is not larger than the value of the argument arg.(向上取整) |
| trunc | Value of the integer part of the argument arg （整数部分） |
| frac | Value of the decimal places of the argument arg （小数部分） |