# Tkinter: Solving a math problem using percentages from 2 entry boxes

I feel like I’m not quite getting the grasp on how to write out Math using Python so I was hoping someone could point me in the right direction. Here’s what I’m trying to do:

X and Y have its own entry box. You type in the two numbers and it’s suppose to give you the percentage between the two. I.e if X = 10 and Y = 9, it’s a 10% difference but with a 77% adjustment. Ignore the point though.

X – Y / X * .77

So far I got:

Note: I had to censor a lot of sensitive labels so please ignore the weird titles for things.

EDIT UPDATED WITH SUGGESTED CODE

```def ---():
Z = StringVar()
Z.set("-")

def roto_calc():
x = (float(first_strip.get())
y = (float(second_strip.get())
Z.set = ((x - y)/ x * .77)
result.config(text=f"{Z}")

yyy = Toplevel(root)
yyy.title("111")
yyy.geometry("400x300")

uuu_frame = LabelFrame(yyy, text=".", height=400)

first_slice = Entry(uuu_frame, font=("Helvetica", 12))

second_slice = Entry(uuu_frame, font=("Helvetica", 12))

result = Label(yyy, textvariable=Z)

submit = Button(yyy, text="Calculate", command=roto_calc)

```

First, you are setting the `text` attribute of the `result` label without ever defining Z. To include variables in Labels you should create a `StringVar()` and then you can use `.set` to set the value.

Secondly, `.get()` returns a string, and you need to convert to `int` or `float` to be able to do calculations.

Thirdly, in the function `xxx` you were using a mix of cases, when you declared the variables as lower case, but then you were using upper case when doing calculations.

```def ---():

Z = StringVar()
Z.set("-")

def xxx():
x = float(first_slice.get())
y = float(second_slice.get())
Z.set(x - y / x * 77)

yyy = Toplevel(root)
yyy.title("111")
yyy.geometry("400x300")

uuu_frame = LabelFrame(yyy, text=".", height=400)