---

Private Sub CommandButton2_Click()
    Dim mass(1 To 15) As Double
    Dim i As Integer
    Dim summ As Double
    Dim inputVal As String
    
    summ = 0
    For i = 1 To 15
        inputVal = InputBox("Введите число " & i & " из 15:", "Ввод чисел")
        If inputVal = "" Then Exit Sub 
        mass(i) = Val(inputVal)
        summ = summ + mass(i)
    Next i
    
    MsgBox "Сумма введенных 15 чисел равна: " & summ, vbInformation, "Результат"
End Sub