title: Grabbing a number from Entry and doing calculations using Tkinter
body: <p>I'm working on my final project for my Intro to Programming classes and I'm having the hardest time working with Tkinter and Python. </p>
  
  <p>Here is my task:
  Have a user enter their income from their paycheck. The program will then do the following calculations: What is 60% of their income for expenses, what is 10% for BOTH short-term and long-term savings and what is 20% of their paycheck for guilt-free spending? </p>
  
  <p>Once the program has completed the calculations, it will then display each of these calculations so the user can make the appropriate transfers with their accounts. </p>
  
  <p><strong>Here is the code I currently have:</strong></p>
  
  <pre><code>from tkinter import *
  from tkinter import ttk
  
  def calculate(*args):
      try:
          value = float(income.get())
          expenses.set(value * .60)
          shortSavings.set(value * .10)
          longSavings.set(value * .10)
          guiltFree.set(value * .20)
  
      except ValueError:
          pass
  
  root = Tk()
  root.title("Monthly Finance Calculater")
  
  mainframe = ttk.Frame(root, padding="3 3 12 12")
  mainframe.grid(column=0, row=0, sticky=(N, W, E, S))
  mainframe.columnconfigure(0, weight=1)
  mainframe.rowconfigure(0, weight=1)
  
  income = StringVar()
  expenses = StringVar()
  shortSavings = StringVar()
  longSavings = StringVar()
  guiltFree = StringVar()
  
  income_entry = ttk.Entry(mainframe, width=7, textvariable=income)
  income_entry.grid(column=2, row=1, sticky=(W, E))
  
  expenses = ttk.Entry(mainframe, width=7, textvariable=expenses)
  expenses.grid(column=2, row=1, sticky=(W, E))
  
  ttk.Label(mainframe, textvariable=income).grid(column=2, row=2, sticky=(W, E))
  ttk.Button(mainframe, text="Calculate", command=calculate).grid(column=3, row=3, sticky=W)
  
  income_entry.focus()
  root.bind('&lt;Return&gt;', calculate)
  
  root.mainloop()
  </code></pre>
  
  <p>I've been searching for days and I'm completely stuck. I don't want this done for me, but could really use some guidance and advice on how to make this work in a GUI using Tkinter.</p>