Type Mismatch Error

Hello,

I am very new to VBA Programing and am still learning my way around things. I know that there is a Type Mismatch error on the Clocksum line but am not sure why. Any tips, pointers, or fixes would be greatly appreciated!

Sub find_problems()

Dim clocknum As Long
Dim ppe As Date
Dim pcode As Long
Dim weeknumber As String
Dim tothrs As Long
Dim clocksum As Long
Dim title1 As String
Dim jobnum As String


Set rclock = range("A2:A10000")   'clock number
Set rppe = range("F2:F10000")   'ppe
Set rhrs = range("Q2:Q10000")   'total hours
Set rweek = range("R2:R10000")   'week

Do While IsEmpty(Selection.Value) = False
    
    clocknum = Selection.Value 'ID Number
    ppe = Selection.Offset(0, 5).Value 'Date
    pcode = Selection.Offset(0, 8).Value 'Pay Code
    tothrs = Selection.Offset(0, 16).Value 'Hours
    weeknumber = Selection.Offset(0, 17).Value 'Week Number
    title1 = Selection.Offset(0, 3).Value 'Job Title
    jobnum = Selection.Offset(0, 6).Value 'Job Number
    
    clocksum = Application.WorksheetFunction.SumProduct((rclock = clocknum) * (rweek = weeknumber) * (rppe = ppe) * (rhrs))

    If clocksum > 120 And (Left(title1, 2) = "FF" Or Left(jobnum, 2) = "asst") Then
        
        Selection.EntireRow.Interior.Color = 50000
        
    ElseIf clocksum <= 40 Then
        
        If pcode = 4242 And tothrs = clocksum Then
            ActiveCell.Offset(1, 0).range("A1").Select
        Else
            Selection.EntireRow.Interior.Color = 50000
        End If
        
    ElseIf clocksum >= 41 And clocksum <= 72 Then
        
        If pcode = 4242 And tothrs = 40 Then
            ActiveCell.Offset(1, 0).range("A1").Select
        ElseIf pcode = 4000 And tothrs = clocksum - 40 Then
            ActiveCell.Offset(1, 0).range("A1").Select
        Else
            Selection.EntireRow.Interior.Color = 50000
            ActiveCell.Offset(1, 0).range("A1").Select
        End If
    ElseIf clocksum >= 73 And clocksum <= 84 Then
        If pcode = 4242 And tothrs = 40 Then
            ActiveCell.Offset(1, 0).range("A1").Select
        ElseIf pcode = 4000 And tothrs = clocksum - 40 Then
            ActiveCell.Offset(1, 0).range("A1").Select
        ElseIf pcode = 8005 And tothrs = clocksum - 72 Then
            ActiveCell.Offset(1, 0).range("A1").Select
        Else
            Selection.EntireRow.Interior.Color = 50000
            ActiveCell.Offset(1, 0).range("A1").Select
        End If

            
        
    End If
    
Loop
    

    
End Sub