C# / .NET - Math.Ceiling() method example

The Math.Ceiling() function returns an integer value that is greater than or equal to the argument - the result of round-up operation. 

using System;

public class Program
{
    public static void Main(string[] args) 
    {
        Console.WriteLine( Math.Ceiling(  5.0  ));  //  5
                                                  
        Console.WriteLine( Math.Ceiling(  2.49 ));  //  3
        Console.WriteLine( Math.Ceiling(  2.50 ));  //  3
        Console.WriteLine( Math.Ceiling(  2.51 ));  //  3
                                                  
        Console.WriteLine( Math.Ceiling( -2.49 ));  // -2
        Console.WriteLine( Math.Ceiling( -2.50 ));  // -2
        Console.WriteLine( Math.Ceiling( -2.51 ));  // -2
                                                   
        Console.WriteLine( Math.Ceiling(  0.999 )); //  1
        Console.WriteLine( Math.Ceiling(  1.001 )); //  2
        Console.WriteLine( Math.Ceiling( -1.001 )); // -1
    }                      
}

1. Documentation

namespace System
{
    public static class Math
    {
        // ...
        public static decimal Ceiling(decimal number) { ... }
        public static double Ceiling(double number) { ... }
        // ...
    }
}

2. Rounding with precision up-to n places example

using System;

public class Program
{
    static double CeilingPrecised(double number, int precision)
    {
        double power = Math.Pow(10, precision);
        return Math.Ceiling(number * power) / power;
    }

    public static void Main(string[] args)
    {
        Console.WriteLine(  CeilingPrecised(  5   , 0  )); // 5
        Console.WriteLine(  CeilingPrecised(  5.0 , 0  )); // 5
        Console.WriteLine(  CeilingPrecised(  0.5 , 0  )); // 1

        Console.WriteLine(  CeilingPrecised(  1.1234, 0  )); // 2
        Console.WriteLine(  CeilingPrecised(  1.1234, 1  )); // 1.2
        Console.WriteLine(  CeilingPrecised(  1.1235, 2  )); // 1.13
        Console.WriteLine(  CeilingPrecised(  1.1235, 3  )); // 1.124
                                                         
        Console.WriteLine(  CeilingPrecised( -1.1234, 0  )); // -1
        Console.WriteLine(  CeilingPrecised( -1.1234, 1  )); // -1.1
        Console.WriteLine(  CeilingPrecised( -1.1234, 2  )); // -1.12
        Console.WriteLine(  CeilingPrecised( -1.1234, 3  )); // -1.123

        Console.WriteLine(  CeilingPrecised(  1234, -1  )); // 1240
        Console.WriteLine(  CeilingPrecised(  1234, -2  )); // 1300
        Console.WriteLine(  CeilingPrecised(  1234, -3  )); // 2000

        Console.WriteLine(  CeilingPrecised(  5_000.000_001,  0 )); // 5001
        Console.WriteLine(  CeilingPrecised(  5_000.000_001,  6 )); // 5000.000001
        Console.WriteLine(  CeilingPrecised(  5_000.000_001, -3 )); // 6000
    }
}

References

1. Floor and ceiling functions - Wikipedia