I code therefore I am.

Integer to Ordinal

public string AddOrdinal(int num)
{
    switch(num % 100)
    {
        case 11:
        case 12:
        case 13:
            return num.ToString() + "th";
    }

    switch(num % 10)
    {
        case 1:
            return num.ToString() + "st";
        case 2:
            return num.ToString() + "nd";
        case 3:
            return num.ToString() + "rd";
        default:
            return num.ToString() + "th";
    }
}