calculator program using tkinter

import tkinter as tk
from tkinter import messagebox
root=tk.Tk()
root.title("My first GUI")
root.geometry("400x400")

tk.Label(root,text="Number 1").pack()
e1=tk.Entry(root)
e1.pack()
tk.Label(root,text="Number 2").pack()
e2=tk.Entry(root)
e2.pack()

def operation1():
    n1=int(e1.get())
    n2=int(e2.get())
    messagebox.showinfo("addition:",f"sum= {n1+n2}")

def operation2():
    n1=int(e1.get())
    n2=int(e2.get())
    messagebox.showinfo("substraction:",f"substraction= {n1-n2}")

def operation3():
    n1=int(e1.get())
    n2=int(e2.get())
    messagebox.showinfo("multiplication:",f"multiplication= {n1*n2}")

def operation4():
    n1=int(e1.get())
    n2=int(e2.get())
    messagebox.showinfo("division:",f"division= {n1/n2}")

tk.Button(root,text="addition",command=operation1).pack()
tk.Button(root,text="substraction",command=operation2).pack()
tk.Button(root,text="multiplication",command=operation3).pack()
tk.Button(root,text="division",command=operation4).pack()


root.mainloop()