Sum Values in different worksheets (same cell) - excel

Question

I have a workbook with multiple sheets ,the number of sheets can change for each project but they all end with PAF. The table is the same across all sheets as well as the cells.
I have a summary tab with the exact same table, I just need to sum it all up there, the table has at least 6 columns and 20 rows so each cell would need the same formula (basically) so I came up with the following but I'm getting an error. Any suggestions?
Sub SumPAF
Dim ws as Worksheet
Sheets("Summary PAF").Activate
For Each ws In ActiveWorkbook.Worksheets
If ws.Name Like "PAF" Then
Range("E10") = WorksheetFunction.Sum(Range("E10"))
End If
Next
End Sub
It's getting stuck in "For Each" saying that an Object is required...

Answer 1

I have commented the code so you should not have a problem understanding it.
Option Explicit
Sub SumPAF()
Dim ws As Worksheet
'~~> This will store the cell addresses
Dim sumFormula As String
'~~> Loop though each worksheet and check if it ends with PAF
'~~> and also to ingore summary worksheet
For Each ws In ActiveWorkbook.Worksheets
If UCase(ws.Name) Like "*PAF" And _
InStr(1, ws.Name, "Summary", vbTextCompare) = 0 Then _
sumFormula = sumFormula & "," & "'" & ws.Name & "'!E10"
'~~> or simply
'sumFormula = sumFormula & ",'" & ws.Name & "'!E10"
Next
'~~> Remove the intital ","
sumFormula = Mid(sumFormula, 2)
'~~> Insert the sum formula
If sumFormula <> "" Then _
Sheets("Summary PAF").Range("E10").Formula = "=SUM(" & sumFormula & ")"
End Sub

Answer 2

Here's a very simple and easy to understand program to illustrate how VBA can be used for loops over ranges. If you have any questions, feel free to ask:
Sub SumPAF()
'Save a reference to the Summary Sheet
Dim SummarySheet As Worksheet
Set SummarySheet = Sheets("Summary PAF")
'Save a reference to the Summary Table and decide the table dimensions
Dim SummaryTable As Range
Set SummaryTable = SummarySheet.Range("A1:F20")
'Create an array to save the sum values
Dim SumValues() As Double
ReDim SumValues(1 To SummaryTable.Rows.Count, 1 To SummaryTable.Columns.Count)
'Loop through the workbook sheets
Dim ws As Worksheet, TableRange As Range
For Each ws In ActiveWorkbook.Worksheets
'Find sheets ending in PAF other than the summary PAF
If ws.Name Like "*PAF" And Not ws.Name = SummarySheet.Name Then
'create a reference to a range on the sheet in the same place and dimensions as the summary table
Set TableRange = ws.Range(SummaryTable.Address)
'loop through the range, cell by cell
Dim i As Long, j As Long
For i = 1 To TableRange.Rows.Count
For j = 1 To TableRange.Columns.Count
'Sum each cell value into the array, where its cell address is the array coordinates.
SumValues(i, j) = SumValues(i, j) + TableRange.Cells(i, j).Value
Next j
Next i
End If
Next
'Output the array into the summary table
SummaryTable.Value = SumValues
End Sub