diff --git a/aula202-calculadora/buttons.py b/aula202-calculadora/buttons.py
index 070ee74..f816d7d 100644
--- a/aula202-calculadora/buttons.py
+++ b/aula202-calculadora/buttons.py
@@ -1,4 +1,5 @@
 from PySide6.QtWidgets import QGridLayout, QPushButton
+from utils import isEmpty, isNumOrDot
 from variables import MEDIUM_FONT_SIZE
 
 
@@ -12,17 +13,27 @@ class Button(QPushButton):
         font.setPixelSize(MEDIUM_FONT_SIZE)
         self.setFont(font)
         self.setMinimumSize(75, 75)
-        self.setProperty('cssClass', 'specialButton')
 
 
 class ButtonsGrid(QGridLayout):
     def __init__(self, *args, **kwargs) -> None:
         super().__init__(*args, **kwargs)
 
-        self._grid_mask = [
+        self._gridMask = [
             ['C', '◀', '^', '/'],
             ['7', '8', '9', '*'],
             ['4', '5', '6', '-'],
             ['1', '2', '3', '+'],
             ['',  '0', '.', '='],
         ]
+        self._makeGrid()
+
+    def _makeGrid(self):
+        for rowNumber, rowData in enumerate(self._gridMask):
+            for colNumber, buttonText in enumerate(rowData):
+                button = Button(buttonText)
+
+                if not isNumOrDot(buttonText) and not isEmpty(buttonText):
+                    button.setProperty('cssClass', 'specialButton')
+
+                self.addWidget(button, rowNumber, colNumber)
diff --git a/aula202-calculadora/main.py b/aula202-calculadora/main.py
index 7a52d3e..3dd527a 100644
--- a/aula202-calculadora/main.py
+++ b/aula202-calculadora/main.py
@@ -1,6 +1,6 @@
 import sys
 
-from buttons import Button, ButtonsGrid
+from buttons import ButtonsGrid
 from display import Display
 from info import Info
 from main_window import MainWindow
diff --git a/aula202-calculadora/utils.py b/aula202-calculadora/utils.py
new file mode 100644
index 0000000..67e662b
--- /dev/null
+++ b/aula202-calculadora/utils.py
@@ -0,0 +1,11 @@
+import re
+
+NUM_OR_DOT_REGEX = re.compile(r'^[0-9.]$')
+
+
+def isNumOrDot(string: str):
+    return bool(NUM_OR_DOT_REGEX.search(string))
+
+
+def isEmpty(string: str):
+    return len(string) == 0