diff --git a/Notebook_clase_4.ipynb b/Notebook_clase_4.ipynb
index 427de98f7aef03c0c692908e2b9b5386a99edd71..e4d96a8b10e8a2fd40d397b4ed00bddd0f83acd9 100644
--- a/Notebook_clase_4.ipynb
+++ b/Notebook_clase_4.ipynb
@@ -19,6 +19,33 @@
    "source": [
     "2+2"
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "26"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "21+5"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {