Tkinter CheckBox command line failing - missing 1 required positional argument: 'self'

I have some code which I intend to run calculations every time a user makes a change to a tkinter widget. If you click in an edit box, or alter the dropdown box the functions run fine. The problem I am having is that I can't get the command line of the CheckBox to accept the functions. It throws a "missing 1 required positional argument: 'self'" while the code works on all other widgets. Can anyone let me know what I'm doing wrong please? Code below:

      #Import everything from tkinter, messageboxes, ttk and math
      from tkinter import *
      from tkinter import ttk

      Form1=Tk()

      # Calculate Variables - Main function. Run every time a change is made to the form
      def CalcVariables(Msg):
      Msg = "Run Calculations"    
      print(Msg)

      #Run Multiple Funtions - Tied to command lines of box functionality
      def MultipleFunctions(*funcs):
          def FuncLoop(*args, **kwargs):
              for f in funcs:
                  f(*args, **kwargs)
          return FuncLoop    

      #Check Length Box entry is Valid
      def LthCheck(Msg):

          #Check entry is numeric - give warning if not and exit
          try:
              float(Lth.get())
          except:
              Msg = "Length box only numbers."
              print(Msg)
              Lth.focus()
              return   

      #Check Width Box Entry is Valid
      def WthCheck(Msg):
          #Check entry is numeric - give warning if not and exit
          try:
              int(Wth.get())
          except ValueError:
              Msg = "Width box only accepts numbers."
              print(Msg)
              Wth.focus()
              return

      #Length EditBox
      Lth = Entry(Form1,width=10)
      Lth.grid(row=0, column=1, sticky=W)
      Lth.insert(0,10)
      Lth.bind("<FocusOut>",MultipleFunctions(LthCheck, CalcVariables))
      Label (Form1, text="Length") .grid(row=0, column=0, sticky=W)

      #Width EditBox
      Wth = Entry(Form1,width=10)
      Wth.grid(row=1, column=1, sticky=W)
      Wth.insert(0,1)
      Wth.bind("<FocusOut>",MultipleFunctions(WthCheck, CalcVariables))
      Label (Form1, text="Width") .grid(row=1, column=0, sticky=W)

      #Type DropDownBox
      Type = [
          "Type 1", 
          "Type 2",
          ]
      PartStyle = StringVar()
      PartStyle.set(Type[0])
      PartStyleDrop = OptionMenu(Form1, PartStyle, *Type, command=MultipleFunctions(LthCheck, WthCheck, CalcVariables))
      PartStyleDrop.grid(row=3, column=1,sticky=W)
      Label (Form1, text="Part") .grid(row=3, column=0, sticky=W)

      #Check Button
      MT = IntVar()
      ModType = Checkbutton(Form1, text = "Modify", variable = MT, onvalue = 1, offvalue =0, command= MultipleFunctions(LthCheck, WthCheck))
      ModType.grid(row=4,column=0)

      Lth.focus()

      Form1.mainloop()