diff --git a/docs/pangeo/xarray_introduction.ipynb b/docs/pangeo/xarray_introduction.ipynb
index 95ee7d4..a2bbbab 100644
--- a/docs/pangeo/xarray_introduction.ipynb
+++ b/docs/pangeo/xarray_introduction.ipynb
@@ -12429,6 +12429,20 @@
     "cams_daily.day"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "9f9cf66f-ec20-4717-9f81-450ce5e98be0",
+   "metadata": {},
+   "source": [
+    "<div class=\"alert alert-warning\">\n",
+    "    <i class=\"fa-check-circle fa\" style=\"font-size: 22px;color:#666;\"></i> <b>Exercise</b>\n",
+    "    <br>\n",
+    "    <ul>\n",
+    "        <li>Could you change the attribute \"value\" from \"hourly values\" to \"daily values\"? </li>\n",
+    "    </ul>\n",
+    "</div>"
+   ]
+  },
   {
    "cell_type": "markdown",
    "id": "935b9333",
@@ -12733,7 +12747,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.11.7"
+   "version": "3.11.9"
   }
  },
  "nbformat": 4,