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Math.Round Method (Decimal, Int32)

.NET Framework 3.0
Rounds a decimal value to a specified number of fractional digits.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

Syntax

```public static decimal Round (
decimal d,
int decimals
)
```
```public static Decimal Round (
Decimal d,
int decimals
)
```
```public static function Round (
d : decimal,
decimals : int
) : decimal
```
```Not applicable.
```

Parameters

d

A decimal number to be rounded.

decimals

The number of decimal places in the return value.

Return Value

The number nearest d with a number of fractional digits equal to decimals.

Exceptions

Exception typeCondition

ArgumentOutOfRangeException

decimals is less than 0 or greater than 28.

OverflowException

The result is outside the range of a Decimal.

Remarks

The decimals parameter specifies the number of fractional digits in the return value and ranges from 0 to 28. If decimals is zero, an integer is returned.

If the value of the digits in d to the right of the decimals position is halfway between the digit in position decimals, that digit is rounded up if it is odd, or left unchanged if it is even. If the precision of d is less than decimals, d is returned unchanged.

The behavior of this method follows IEEE Standard 754, section 4. This kind of rounding is sometimes called rounding to nearest, or banker's rounding. It minimizes rounding errors that result from consistently rounding a midpoint value in a single direction.

To control the type of rounding used by the Round(Decimal,Int32) method, call the Decimal.Round(Decimal,Int32,MidpointRounding) overload.

Example

The following example demonstrates rounding to nearest.

```Math.Round(3.44, 1); //Returns 3.4.
Math.Round(3.45, 1); //Returns 3.4.
Math.Round(3.46, 1); //Returns 3.5.

```
```System.Math.Round(3.44, 1); //Returns 3.4.
System.Math.Round(3.45, 1); //Returns 3.4.
System.Math.Round(3.46, 1); //Returns 3.5.

```
```System.Math.Round(3.44, 1) //Returns 3.4.
System.Math.Round(3.45, 1) //Returns 3.4.
System.Math.Round(3.46, 1) //Returns 3.5.

```

Platforms

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

Version Information

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0