title: "Could not convert string to float:''
body: <p>I am a very beginner in terms of coding. I am trying to calculate the sum of the order but python keeps telling me that it could not convert the string to float. Could you please show me where the error lies?</p>
  <pre><code>import tkinter as tk
  
  window = tk.Tk()
  
  window.title(&quot;Cinema&quot;)
  window.geometry(&quot;700x600&quot;)
  
  def total_():
      a= float(e1.get())*2
      b= float(e2.get())*3
      c= float(e3.get())*4
      d= float(e5.get())*1
      e= float(e4.get())*12
      totl = a+b+c+d+e
      tax= (totl * 0.13 + 0.13)
      lblAns['text'] = &quot;Your total is {}$&quot;.format(totl)
  
  #Cinema name
  Cine_nom = tk.Label(window)
  Cine_nom['text'] = &quot;Welcome to cinema !&quot;
  Cine_nom['font'] = &quot;Arial 20 bold&quot;
  Cine_nom.place(x=350, y=20, anchor=&quot;center&quot;)
  
  # Menu Creation
  label1 = tk.Label(window,
  text=&quot;Menu&quot;,
  font=&quot;times 28 bold&quot;)
  
  label1.place(x=520, y=70)
  
  label2 = tk.Label(window, text=&quot;Popcorn (P) \
  2$&quot;, font=&quot;times 18&quot;)
  
  label2.place(x=450, y=120)
  
  label3 = tk.Label(window, text=&quot;Popcorn (M) \
  3$&quot;, font=&quot;times 18&quot;)
  
  label3.place(x=450, y=150)
  
  label4 = tk.Label(window, text=&quot;Popcorn (L) \
  4$&quot;, font=&quot;times 18&quot;)
  label4.place(x=450, y=180)
  
  label5 = tk.Label(window, text=&quot;Burger Combo \
  12$&quot;, font=&quot;times 18&quot;)
  
  label5.place(x=450, y=210)
  
  label6 = tk.Label(window, text=&quot;Soda \
  1$&quot;, font=&quot;times 18&quot;)
  
  label6.place(x=450, y=240)
  
  # Entry Table
  label9 = tk.Label(window, text=&quot;Select the items&quot;,
  font=&quot;times 18&quot;)
  label9.place(x=115, y=70)
  
  label10 = tk.Label(window,
  text=&quot;Popcorn (P)&quot;,
  font=&quot;times 18&quot;)
  label10.place(x=20, y=120)
  
  e1 = tk.Entry(window)
  e1.place(x=20, y=150)
  
  label11 = tk.Label(window, text=&quot;Popcorn (M)&quot;,
  font=&quot;times 18&quot;)
  label11.place(x=20, y=200)
  
  e2= tk.Entry(window)
  e2.place(x=20, y=230)
  
  label12 = tk.Label(window, text=&quot;Popcorn (L)&quot;,
  font=&quot;times 18&quot;)
  label12.place(x=20, y=280)
  
  e3= tk.Entry(window)
  e3.place(x=20, y=310)
  
  label13 = tk.Label(window,
  text=&quot;Burger Combo&quot;,
  font=&quot;times 18&quot;)
  label13.place(x=20, y=360)
  
  e4 = tk.Entry(window)
  e4.place(x=20, y=390)
  
  label14 = tk.Label(window,
  text=&quot;Soda&quot;,
  font=&quot;times 18&quot;)
  label14.place(x=20, y=420)
  e5 = tk.Entry(window)
  e5.place(x=20, y=450)
  
  # Button for total
  btnCalculate = tk.Button(window)
  btnCalculate['text'] = &quot;Calculate your bill&quot;
  btnCalculate['font'] = &quot;Arial 15&quot;
  btnCalculate['command'] = total_
  btnCalculate.place(x=30, y=480)
  
  lblAns = tk.Label(window)
  lblAns['text'] = &quot;&quot;
  lblAns.place(x=40, y=700)
  
  window.mainloop()
  </code></pre>