How to round a integer to the close hundred?

Question

I don\'t know it my nomenclature is correct! Anyway, these are the integer I have, for example :

76
121
9660

And I\'d like to round them to

Answer 1

Hi i write this extension this gets the next hundred for each number you pass

/// 

    /// this extension gets the next hunfìdred for any number you whant
    /// 
    /// numeber to rounded
    /// the next hundred number
    /// 
    /// eg.:
    /// i =   21 gets 100
    /// i =  121 gets 200
    /// i =  200 gets 300
    /// i = 1211 gets 1300
    /// i = -108 gets -200
    /// 
    public static int RoundToNextHundred(this int i)
    {
        return i += (100 * Math.Sign(i) - i % 100);
        //use this line below if you want RoundHundred not NEXT
        //return i % 100 == byte.MinValue? i : i += (100 * Math.Sign(i) - i % 100);
    }

    //and for answer at title point use this algoritm
    var closeHundred = Math.Round(number / 100D)*100;

    //and here the extension method if you prefer

    /// 

    /// this extension gets the close hundred for any number you whant
    /// 
    /// number to be rounded
    /// the close hundred number
    /// 
    /// eg.:
    /// number =   21 gets    0
    /// number =  149 gets  100
    /// number =  151 gets  200
    /// number = -149 gets -100
    /// number = -151 gets -200
    /// 
    public static int RoundCloseHundred(this int number)
    {
        return (int)Math.Round(number / 100D) * 100;
    }