using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace WindowsFormsApp5
{
    public static class SomeClass
    {
        private static readonly string superscripts = @"⁰¹²³⁴⁵⁶⁷⁸⁹";
        public static string ToSuperscriptNumber_(this int @this)
        {
            var sb = new StringBuilder();
            Stack<byte> digits = new Stack<byte>();
            do
            {
                var digit = (byte)(@this % 10);
                digits.Push(digit);
                @this /= 10;
            } while (@this != 0);
            while (digits.Count > 0)
            {
                var digit = digits.Pop();
                sb.Append(superscripts[digit]);
            }
            return sb.ToString();
        }
    }
    public static class SuperscriptNumber
    {
        //https://stackoverflow.com/questions/15042334/how-can-i-add-superscript-power-operators-in-c-sharp-winforms
        //https://en.wikipedia.org/wiki/Unicode_subscripts_and_superscripts
        //https://stackoverflow.com/questions/19682459/superscript-label-or-form-name
        private static readonly string superscripts = @"0123456789+-";
        private static string ToSuperscriptNumber(this int @this)
        {
            var sb = new StringBuilder();
            var digits = @this.ToString().ToArray();
            foreach (var digit in digits)
            {
                if (digit == '0')
                {
                    sb.Append(("\u2070"));
                }
                else if (digit == '1')
                {
                    sb.Append(("\u00B9"));
                }
                else if (digit == '2')
                {
                    sb.Append(("\u00B2"));
                }
                else if (digit == '3')
                {
                    sb.Append(("\u00B3"));
                }
                else if (digit == '4')
                {
                    sb.Append(("\u2074"));
                }
                else if (digit == '5')
                {
                    sb.Append(("\u2075"));
                }
                else if (digit == '6')
                {
                    sb.Append(("\u2076"));
                }
                else if (digit == '7')
                {
                    sb.Append(("\u2077"));
                }
                else if (digit == '8')
                {
                    sb.Append(("\u2078"));
                }
                else if (digit == '9')
                {
                    sb.Append(("\u2079"));
                }
                else if (digit == '+')
                {
                    sb.Append(("\u207A"));
                }
                else if (digit == '-')
                {
                    sb.Append(("\u207B"));
                }
            }
            return sb.ToString();
        }
        public static string ToSuperScript(this int number)
        {
            if (number == 0 ||
                number == 1)
                return "";
            const string SuperscriptDigits =
                "\u2070\u00b9\u00b2\u00b3\u2074\u2075\u2076\u2077\u2078\u2079";
            string Superscript = "";
            if (number < 0)
            {
                //Adds superscript minus
                Superscript = ((char)0x207B).ToString();
                number *= -1;
            }

            Superscript += new string(number.ToString()
                                            .Select(x => SuperscriptDigits[x - '0'])
                                            .ToArray()
                                      );
            return Superscript;
        }
        public static string ToSuperscriptNumber(this string @this)
        {
            var a = @this.Trim().Split('^');
            string s = "";
            if (a.Length == 2)
            {
                string _a = a[0].Trim();
                int _b = int.Parse(a[1].Trim());
                s = _a + _b.ToSuperscriptNumber();
            }
            return s;
        }
    }
}

 private void pictureBox1_Paint(object sender, PaintEventArgs e)
        {
            int yC = 20;
            for (int i = 1; i < 20; i++)
            {
                 e.Graphics.DrawString($"{random .Next(1,10) +  random.Next(1,10).ToSuperScript()}  + {random.Next(1, 10) +  random.Next(1, 10).ToSuperScript()} - {random.Next(1, 10) +  random.Next(1, 10).ToSuperScript()}= " ,
                            new Font("Cordia New", 20), new SolidBrush(Color.Black), 50, yC);
              
                yC += 50;
            }
          
        }