I want to get round value as below:

If it is equal to 646.50 then the rounded value should be 647.00 [Here, I am getting the result as 646.00]

If it is equal to 646.49 then the rounded value should be 646.00

Note: What I mean is, If the decimal value is less than or equal to .49 then it should deduct 1 from the Invoice value, and if it is equal or greater than .50 then it should add 1 to the Invoice value. How to modify the below code?

Code:

Dim var1 As Decimal = InvoiceValue 'Assign original value here.
Dim var2 As Decimal = Math.Round(var1)
Dim var3 As Decimal = var2 - var1
Dim FRoundOff As Double
Dim FRoundUp As Double
FRoundOff = var3
txtRoundOff.Text = FRoundOff.ToString("n2")
If FRoundOff <= 0.5 Then
FRoundUp = InvoiceValue + FRoundOff
Else
FRoundUp = InvoiceValue - FRoundOff
End If
txtTotalInvoiceValue.Text = FRoundUp.ToString("n2")