Decimal.Round Method (Decimal)
Note 

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Rounds a decimal value to the nearest integer.
Assembly: mscorlib (in mscorlib.dll)
Parameters
 d

Type:
System.Decimal
A decimal number to round.
Return Value
Type: System.DecimalThe integer that is nearest to the d parameter. If d is halfway between two integers, one of which is even and the other odd, the even number is returned.
Exception  Condition 

OverflowException  The result is outside the range of a Decimal value. 
The behavior of this method follows IEEE Standard 754, section 4. This kind of rounding is sometimes called round half to even or banker's rounding. It minimizes rounding errors that result from consistently rounding a midpoint value in a single direction. It is equivalent to calling the Round(Decimal, MidpointRounding) method with a mode argument of MidpointRounding.ToEven.
Available since 2.0