計算ツールを作成したい

import math
import tkinter as tk

from typing import Self

class Application:
    # インスタンスの初期化
    def __init__ (self: Self) -> None:
        self._build_gui()
    # GUIの構築
    def _build_gui (self: Self) -> None:
        # ルート領域の作成
        root: tk.Tk = ...
        root.title(...)
        ...
        # 背景用？
        canvas: tk.Canvas = ...
        canvas.place(...)
        # ラベルの作成
        label1: tk.Label = ...
        label1.place(...)
        label2: tk.Label = ...
        label2.place(...)
        label3: tk.Label = ...
        label3.place(...)
        label4: tk.Label = ...
        label4.place(...)
        # 入力欄の作成
        entry1: tk.Entry = ...
        entry1.place(...)
        entry2: tk.Entry = ...
        entry2.place(...)
        entry3: tk.Entry = ...
        entry3.place(...)
        entry4: tk.Entry = ...
        entry4.place(...)
        # ボタンの作成
        button1: tk.Button = ...
        button1.place(...)
        # 非Public変数に紐付け(計算処理で参照する)
        self._entry1: tk.Entry = entry1
        self._entry2: tk.Entry = entry2
        self._entry3: tk.Entry = entry3
        self._entry4: tk.Entry = entry4
    # 入力値の計算
    def _calc (self: Self) -> None:
        # 入力値の読み取り
        text1: str = self._entry1.get()
        mark: str = str(self._entry2.get())
        text3: str = self._entry3.get()
        # 数値変換(空白時は0で初期化)
        val1: float = float(text1) if text1 != '' else 0
        val2: float = float(text3) if text3 != '' else 0
        # 回答の定義
        ret: float = 0.0
        # 記号に応じて計算(関数にせず、ここで算出)
        match mark:
            case '+': ret = ...
            case '-': ret = ...
            ...
            case _: return
        # 回答の出力
        self._entry4.delete(0, tk.END)
        self._entry4.insert(0, ret)
    # アプリケーションの表示
    def _show (self: Self) -> None:
        self._root.mainloop()
    # アプリケーションの機動
    @staticmethod
    def launch () -> None:
        app: Application = Application()
        app._show()

if __name__ == '__main__':
    Application.launch()

import tkinter
import math

def num_one():
    return int(one.get())

def num_two():
    return int(two.get())

def sum():
    return num_one()+num_two()

def minus():
    return num_one()-num_two()

def inc():
    return num_one()*num_two()

def div():
    return num_one()/num_two()

def div2():
    return num_one()//num_two()

def joe():
    return num_one()**num_two()

def extra():
    return num_one()%num_two()

def circle():
    return round(math.pi**num_one(),2)

def bottom():
    return math.log2(num_one())

def sqrt():
    return math.sqrt(num_one())

def sin():
    return round(math.sin(math.radians(num_one())))

def cos():
    return round(math.cos(math.radians(num_one())))

def tan():
    return math.tan(math.radians(num_one()))

functions = {
    '+': sum,
    '-': minus,
    '*': inc,
    '/': div,
    '//': div2,
    '**': joe,
    '%': extra,
    'pi': circle,
    'log2': bottom,
    'sqrt': sqrt,
    'sin': sin,
    'cos': cos,
    'tan': tan,
}

def calc():
    try:
        answer['text']=functions[mark.get()]()
    except (KeyError, ValueError, ZeroDivisionError):
        answer['text']='ERROR'

root=tkinter.Tk()
root.title("偉大なる頭脳")
root.minsize(600,580)
root.option_add("*font",["MS ゴシック",20])

canvas=tkinter.Canvas(bg="#99ff22",width=700,height=480)
canvas.place(x=0,y=0)

guide=tkinter.Label(text="1つ目の数字を入力してね",bg="#99ff22")
guide.place(x=80,y=50)

one=tkinter.Entry(width=12,bd=4)
one.place(x=400,y=50)

guide2=tkinter.Label(text="記号",bg="#99ff22")
guide2.place(x=80,y=150)

mark=tkinter.Entry(width=12,bd=4)
mark.place(x=400,y=150)

guide3=tkinter.Label(text="2つ目の数字を入力してね",bg="#99ff22")
guide3.place(x=80,y=250)

two=tkinter.Entry(width=12,bd=4)
two.place(x=400,y=250)

guide4=tkinter.Label(text="回答",bg="#99ff22")
guide4.place(x=80,y=350)

answer=tkinter.Label(width=12,bd=4)
answer.pack(pady=10)
answer.place(x=400,y=350)

askbutton=tkinter.Button(master=root,text="計算する",command=calc)
askbutton.place(x=240,y=350)

root.mainloop()