Integers are rounded decimals are only taken to 2 decimal places and rounded

The cell value is an integer, and the integer is reserved, but the cell value has a decimal point, and only 2 decimal points can be reserved

4 rounded to 5

Column J is the input area, and the data will immediately get results like column L after input

Column L does not exist, it is just a reference value

congratulations merry christmas everyone

Any help would be appreciated!

Try

=IF(MOD($J2,1)=0,$J2,ROUND($J2,2))

You will need VBA if you want result in the input cell

Private Sub Worksheet_Change(ByVal Target As Range)
    If Not Intersect(Target, Range("J1:J100")) Is Nothing Then
    
        If Int(Target.Value) <> Target.Value Then
        Target.Value = Application.RoundUp(Target.Value, 2)
        End If
    End If
    Application.EnableEvents = True
End Sub

Right Click on sheet tab, "View Code", copy/paste above code.

In M2 copied down

=IF(J2="","",CEILING(J2,0.01))