# Tk_arrowkey_int_scroll.py

# Tk_arrowkey_int_scroll.py

from Tkinter import *

def up(event):
    old = int(event.widget.get()) # this gives back the actual object!
    event.widget.delete(0, END) # delete existing text
    event.widget.insert(10, old + 1) # put new text in

def down(event):
    old = int(event.widget.get()) # this gives back the actual object!
    event.widget.delete(0, END) # delete existing text
    event.widget.insert(10, old - 1) # put new text in

root = Tk()

A = Entry(root, width=4, font=("Helvetica", 16)) #  Entry A
A.insert(10, 64)
A.grid(row=1, column=1)

B = Entry(root, width=4, font=("Helvetica", 16)) #  Entry B
B.insert(10, 100)
B.grid(row=1, column=2)

C = Entry(root, width=4, font=("Helvetica", 16)) #  Entry C
C.insert(10, 6)
C.grid(row=1, column=3)

# bind both keys to corresponding event handlers
root.bind('<Up>', up)
root.bind('<Down>', down)
mainloop()