part 2 of 2 of walkthrough
Code:
 Case 10
                Select Case N \ 1000000000
                    Case 1
                        kanji = "ju" & " " & toKanji(N Mod 1000000000)
                    Case 2
                        kanji = "ni-ju" & " " & toKanji(N Mod 1000000000)
                    Case 3
                        kanji = "san-ju" & " " & toKanji(N Mod 1000000000)
                    Case 4
                        kanji = "yon-ju" & " " & toKanji(N Mod 1000000000)
                    Case 5
                        kanji = "go-ju" & " " & toKanji(N Mod 1000000000)
                    Case 6
                        kanji = "roku-ju" & " " & toKanji(N Mod 1000000000)
                    Case 7
                        kanji = "nana-ju" & " " & toKanji(N Mod 1000000000)
                    Case 8
                        kanji = "hachi-ju" & " " & toKanji(N Mod 1000000000)
                    Case 9
                        kanji = "kyu-ju" & toKanji(N Mod 1000000000)
                    Case Else
                        kanji = ""
                End Select
            Case 11
                Select Case N \ 10000000000
                    Case 1
                        kanji = "hyaku" & " " & toKanji(N Mod 10000000000)
                    Case 2
                        kanji = "ni-hyaku" & " " & toKanji(N Mod 10000000000)
                    Case 3
                        kanji = "sanbyaku" & " " & toKanji(N Mod 10000000000)
                    Case 4
                        kanji = "yon-hyaku" & " " & toKanji(N Mod 10000000000)
                    Case 5
                        kanji = "go-hyaku" & " " & toKanji(N Mod 10000000000)
                    Case 6
                        kanji = "roku-hyaku" & " " & toKanji(N Mod 10000000000)
                    Case 7
                        kanji = "nana-hyaku" & " " & toKanji(N Mod 10000000000)
                    Case 8
                        kanji = "hapyaku" & " " & toKanji(N Mod 10000000000)
                    Case 9
                        kanji = "kyu-hyaku" & toKanji(N Mod 10000000000)
                    Case Else
                        kanji = ""
                End Select
            Case 12
                Select Case N \ 100000000000
                    Case 1
                        kanji = "sen" & " " & toKanji(N Mod 100000000000)
                    Case 2
                        kanji = "ni-sen" & " " & toKanji(N Mod 100000000000)
                    Case 3
                        kanji = "sanzen" & " " & toKanji(N Mod 100000000000)
                    Case 4
                        kanji = "yon-sen" & " " & toKanji(N Mod 100000000000)
                    Case 5
                        kanji = "go-sen" & " " & toKanji(N Mod 100000000000)
                    Case 6
                        kanji = "roku-sen" & " " & toKanji(N Mod 100000000000)
                    Case 7
                        kanji = "nana-sen" & " " & toKanji(N Mod 100000000000)
                    Case 8
                        kanji = "hassen" & " " & toKanji(N Mod 100000000000)
                    Case 9
                        kanji = "kyu-sen" & toKanji(N Mod 100000000000)
                    Case Else
                        kanji = ""
                End Select
            Case 13
                Select Case N \ 1000000000000
                    Case 1
                        kanji = "itcho" & " " & toKanji(N Mod 1000000000000)
                    Case 2
                        kanji = "ni-cho" & " " & toKanji(N Mod 1000000000000)
                    Case 3
                        kanji = "san-cho" & " " & toKanji(N Mod 1000000000000)
                    Case 4
                        kanji = "yon-cho" & " " & toKanji(N Mod 1000000000000)
                    Case 5
                        kanji = "go-cho" & " " & toKanji(N Mod 1000000000000)
                    Case 6
                        kanji = "roku-cho" & " " & toKanji(N Mod 1000000000000)
                    Case 7
                        kanji = "nana-cho" & " " & toKanji(N Mod 1000000000000)
                    Case 8
                        kanji = "hatcho" & " " & toKanji(N Mod 1000000000000)
                    Case 9
                        kanji = "kyu-cho" & toKanji(N Mod 1000000000000)
                    Case Else
                        kanji = ""
                End Select
            Case 14
                Select Case N \ 10000000000000
                    Case 1
                        kanji = "ju" & " " & toKanji(N Mod 10000000000000)
                    Case 2
                        kanji = "ni-ju" & " " & toKanji(N Mod 10000000000000)
                    Case 3
                        kanji = "san-ju" & " " & toKanji(N Mod 10000000000000)
                    Case 4
                        kanji = "yon-ju" & " " & toKanji(N Mod 10000000000000)
                    Case 5
                        kanji = "go-ju" & " " & toKanji(N Mod 10000000000000)
                    Case 6
                        kanji = "roku-ju" & " " & toKanji(N Mod 10000000000000)
                    Case 7
                        kanji = "nana-ju" & " " & toKanji(N Mod 10000000000000)
                    Case 8
                        kanji = "hachi-ju" & " " & toKanji(N Mod 10000000000000)
                    Case 9
                        kanji = "kyu-ju" & toKanji(N Mod 10000000000000)
                    Case Else
                        kanji = ""
                End Select
            Case 15
                Select Case N \ 100000000000000
                    Case 1
                        kanji = "hyaku" & " " & toKanji(N Mod 100000000000000)
                    Case 2
                        kanji = "ni-hyaku" & " " & toKanji(N Mod 100000000000000)
                    Case 3
                        kanji = "sanbyaku" & " " & toKanji(N Mod 100000000000000)
                    Case 4
                        kanji = "yon-hyaku" & " " & toKanji(N Mod 100000000000000)
                    Case 5
                        kanji = "go-hyaku" & " " & toKanji(N Mod 100000000000000)
                    Case 6
                        kanji = "roku-hyaku" & " " & toKanji(N Mod 100000000000000)
                    Case 7
                        kanji = "nana-hyaku" & " " & toKanji(N Mod 100000000000000)
                    Case 8
                        kanji = "hapyaku" & " " & toKanji(N Mod 100000000000000)
                    Case 9
                        kanji = "kyu-hyaku" & toKanji(N Mod 100000000000000)
                    Case Else
                        kanji = ""
                End Select
            Case 16
                Select Case N \ 1000000000000000
                    Case 1
                        kanji = "sen" & " " & toKanji(N Mod 1000000000000000)
                    Case 2
                        kanji = "ni-sen" & " " & toKanji(N Mod 1000000000000000)
                    Case 3
                        kanji = "sanzen" & " " & toKanji(N Mod 1000000000000000)
                    Case 4
                        kanji = "yon-sen" & " " & toKanji(N Mod 1000000000000000)
                    Case 5
                        kanji = "go-sen" & " " & toKanji(N Mod 1000000000000000)
                    Case 6
                        kanji = "roku-sen" & " " & toKanji(N Mod 1000000000000000)
                    Case 7
                        kanji = "nana-sen" & " " & toKanji(N Mod 1000000000000000)
                    Case 8
                        kanji = "hassen" & " " & toKanji(N Mod 1000000000000000)
                    Case 9
                        kanji = "kyu-sen" & toKanji(N Mod 1000000000000000)
                    Case Else
                        kanji = ""
                End Select
            Case Else

        End Select


        Return kanji
    End Function
    Private Sub TextBox1_KeyUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyUp
        Try
            Dim dnum As ULong
            dnum = TextBox1.Text
            If dnum = 0 Then
                Label1.Text = "rei"
            Else
                Label1.Text = toKanji(dnum)
            End If
        Catch ex As Exception
            MsgBox("enter an integer up to 16 digits , text length : " & TextBox1.Text.Length())
        End Try
    End Sub
End Class
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