Creating an array of checkboxes tied to a single list with tkinter?

I'm trying to make a window that will provide a grid of checkboxes that looks like this: grid of checkboxes 10x10

I've got the following code to create it:

checks = Tk()
    checks.title("Check Grid")
    value = []
    z = 1
    for x in range(1,11): # Row
        for y in range(1,11): # Column
            value.append('')
            box = Checkbutton(checks, text = z, variable = value[(z)-1])
            box.grid(row = x, column = y, sticky = S)
            z += 1
    #exit button
    def exit():
        print(value)
        checks.destroy()
    Label = Button(checks, text = 'Exit',command = exit).grid(row = 11)
    checks.mainloop()

    return value`

with this: box = Checkbutton(checks, text = z, variable = value[(x*y)-1]) I'm trying to assign the checkbox value to the z value of the value list. This doesn't appear to be working, any ideas?

question: How do I make a grid of checkboxes, using tkinter, that send their values to their list index of a single list?