Number.Round Function of Power Query
The Number.Round function in Power Query returns a nullable number (n) if value is an integer.
Syntax
Number.Round( number as nullable number, optional digits as nullable number, optional roundingMode as nullable number) as nullable number
Example: Round the number 1.234 to the nearest integer.
Power Query M
let
    source = Number.Round(1.234)
in
    source   The output of the above code is 1.
Example: Round the number 2.6 to the nearest integer.
Power Query M
let
    source = Number.Round(2.6)
in
    source  The output of the above code is 3.
Example: Round the number 2.247 to two decimal places.
Power Query M
let
    source = Number.Round(2.247,2)
in
    source  The output of the above code is 2.25.