Turn Off Automatic Calculations for Single Worksheet or Workbook, NOT ALL WORKBOOKS

I have a workbook with multiple worksheets and I want this workbook, and all of the worksheets to be set to "Manual Calculations" but don't want to turn off "Automatic Calculations" for ALL of Excel.

I have entered this code in each worksheet and added it as a Module to the Workbook but it isn't working:

Option Explicit
 
Private Sub Worksheet_Activate()
    Application.Calculation = xlCalculationAutomatic
     
End Sub
 
Private Sub Worksheet_Deactivate()
    Application.Calculation = xlCalculationManual
     
End Sub

Am I entering it in the wrong place, is it the wrong code, am I just missing something or all of the above?