diff --git a/docs-2.0/3.ngql-guide/6.functions-and-expressions/1.math.md b/docs-2.0/3.ngql-guide/6.functions-and-expressions/1.math.md
index f235aefacff..1cd0fed6eb4 100644
--- a/docs-2.0/3.ngql-guide/6.functions-and-expressions/1.math.md
+++ b/docs-2.0/3.ngql-guide/6.functions-and-expressions/1.math.md
@@ -9,7 +9,7 @@ Function| Description |
 double abs(double x) | Returns the absolute value of the argument. |
 double floor(double x) | Returns the largest integer value smaller than or equal to the argument. (Rounds down) |
 double ceil(double x) | Returns the smallest integer greater than or equal to the argument. (Rounds up) |
-double round(double x) | Returns the integer value nearest to the argument. Returns a number farther away from 0 if the argument is in the middle. |
+double round(double x, int y) | Returns the rounded value of x. y specifies the rounding index (position). If y is greater than 0, round at the yth position to the right of the decimal point. If y is less than 0, round at the yth position to the left of the decimal point. <br>Pay attention to the floating-point precision when using this function. |
 double sqrt(double x) | Returns the square root of the argument. |
 double cbrt(double x) | Returns the cubic root of the argument. |
 double hypot(double x, double y) | Returns the hypotenuse of a right-angled triangle. |