Function CountTheOnes(aArray As Variant) As Long
    Dim x As Long
    Dim OnesCount As Long
    For x = LBound(aArray) To UBound(aArray)
        If aArray(x) = 1 Then
            OnesCount = OnesCount + 1
        End If
    Next
    CountTheOnes = OnesCount
End Function

' and to test it:

Sub TestIt()
    Dim aArray(1 To 10) As Byte
    Dim x As Long

    ' stuff the array with zeros
    For x = LBound(aArray) To UBound(aArray)
        aArray(x) = 0
    Next

    ' then add a couple of random 1s
    aArray(3) = 1
    aArray(7) = 1
    aArray(9) = 1


    x = CountTheOnes(aArray)

    Debug.Print "Ones:" & vbTab & x
    Debug.Print "Zeros:" & vbTab & UBound(aArray) - x

End Sub

x = Application.WorksheetFunction.Sum(aArray)