Ввод массива чисел в многострочном поле

Public Class Form1
    Dim A(), SUM, PRO, RAZ As Double
    'Для синхронизации полос прокрутки от OVVA
    Const WM_USER As Integer = &H400
    Const EM_GETSCROLLPOS As Integer = WM_USER + 221
    Const EM_SETSCROLLPOS As Integer = WM_USER + 222
    Declare Function SendMessage Lib "user32.dll" Alias "SendMessageW" (ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wParam As Integer, ByRef lParam As Point) As Integer
    '…
    Private Sub RichTextBox1_VScroll(sender As Object, e As EventArgs) Handles RichTextBox1.VScroll
        Dim pt As Point
        SendMessage(RichTextBox1.Handle, EM_GETSCROLLPOS, 0, pt)
        SendMessage(RichTextBox2.Handle, EM_SETSCROLLPOS, 0, pt)
    End Sub
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        For i = 0 To 98
            RichTextBox2.Text &= "A(" & i & ")=" & vbNewLine
            Button2.Enabled = False
        Next
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        ListBox1.Items.Clear()
        Button2.Enabled = True
        Try
            'oчищаем переменные
            PRO = 1
            SUM = 0
            'Удаляем пустые строки
            RichTextBox1.Text = RichTextBox1.Text.Replace(New Char() {vbLf, vbCr}, "").TrimEnd(New Char() {vbLf, vbCr})
            RichTextBox1.Text = RichTextBox1.Text.Replace(".", ",") 'меняем точки на запятые
 
            For i = 0 To RichTextBox1.Lines.Count - 1
                ReDim Preserve A(i) 'Инициализируем массив
                A(i) = CDbl(RichTextBox1.Lines(i))
                ListBox1.Items.Add("A(" & i & ")=" & A(i))
                SUM += A(i)
                PRO *= A(i)
            Next
            ListBox1.Items.Add("Сумма=" & SUM)
            ListBox1.Items.Add("Произведение=" & PRO)
        Catch ex As Exception
            '  MsgBox(ex.ToString)
        End Try
 
    End Sub
 
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        RAZ = A(0)
        For i = 1 To UBound(A) - 1
            RAZ -= A(i)
        Next
        ListBox1.Items.Add("Разность=" & RAZ)
    End Sub
End Class

Public Class Form4
    Private n As Integer
    Private Sub Form4_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        n = 10 
        With DataGridView1
            .Columns.Add("nm", "Name")
            .Columns.Add("vv", "Value")
            .Columns(1).ValueType = GetType(Double)
            For i = 0 To n - 1
                .Rows.Add({"a" & (i + 1).ToString, 0})
            Next
            .AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill
            .Rows.Add(1)
        End With
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Sample("Max")
    End Sub
 
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Sample("Sum")
    End Sub
 
    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        Sample("Average")
    End Sub
 
    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
        Sample("Multiplication")
    End Sub
 
    Private Sub Sample(tt As String)
        Dim aa(n - 1) As Double
        For i = 0 To n - 1
            aa(i) = DataGridView1.Rows(i).Cells(1).Value
        Next
        DataGridView1.Rows(n).Cells(0).Value = tt & " ="
        Select Case tt
            Case "Max"
                DataGridView1.Rows(n).Cells(1).Value = aa.Max
            Case "Sum"
                DataGridView1.Rows(n).Cells(1).Value = aa.Sum
            Case "Average"
                DataGridView1.Rows(n).Cells(1).Value = aa.Average
            Case "Multiplication"
                DataGridView1.Rows(n).Cells(1).Value = aa.Aggregate(Function(t1, t2) t1 * t2)
        End Select
        DataGridView1.FirstDisplayedCell = DataGridView1.Rows(n).Cells(0)
        DataGridView1.Rows(n).Cells(1).Selected = True
    End Sub
End Class