Added unplanned activity from class today, fixed typo

Author: davewhipp

notebooks/L4/functions.ipynb

@@ -137,7 +137,44 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Funtions within a function (Yo dawg...)\n",
+    "<hr>\n",
+    "\n",
+    "#### Check your understanding\n",
+    "\n",
+    "Let's see how things are going so far with functions. In the Python cell below, please:\n",
+    "\n",
+    "- Create a new function called `hello` with 2 parameters\n",
+    "    - Parameter 1 should be called `name` and you should assign some text to this parameter this when using the function\n",
+    "    - Parameter 2 should be called `age` and you should provide a number value for this parameter when using the function\n",
+    "\n",
+    "When using your function, the value that is returned should be a character string stating the `name` and `age` that were provided, which you can assign to a variable called `output`.\n",
+    "Printing out `output` should produce something like the following:\n",
+    "\n",
+    "```python\n",
+    "print(output)\n",
+    "'Hello, my name is Dave. I am 38 years old.'\n",
+    "```"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "<hr>"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Functions within a function (Yo dawg...)\n",
     "\n",
     "What about converting Kelvins to Fahrenheit?\n",
     "We could write out a new formula for it, but we don’t need to.\n",