Convert number to native digits

    public static string ToNativeDigits(this string text, CultureInfo culture = null)
    {
        culture = culture ?? CultureInfo.CurrentCulture;
        var nativeDigits = culture.NumberFormat.NativeDigits;
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < text.Length; i++)
        {
            char c = text[i];
            if (c >= '0' && c <= '9')
            {
                int v = (int)(c - '0');
                string nc = nativeDigits[v];
                sb.Append(nc);
            }
            else
            {
                sb.Append(c);
            }
        }
        return sb.ToString();
    }