diff --git a/01_Getting_&_Knowing_Your_Data/Chipotle/Exercise_with_Solutions.ipynb b/01_Getting_&_Knowing_Your_Data/Chipotle/Exercise_with_Solutions.ipynb
index a5467d269..9a42401be 100644
--- a/01_Getting_&_Knowing_Your_Data/Chipotle/Exercise_with_Solutions.ipynb
+++ b/01_Getting_&_Knowing_Your_Data/Chipotle/Exercise_with_Solutions.ipynb
@@ -473,7 +473,26 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 13. How much was the revenue for the period in the dataset?"
+    "### Step 13. Turn the item price into a float"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": [
+    "dollarizer = lambda x: float(x[1:-1])\n",
+    "chipo.item_price = chipo.item_price.apply(dollarizer)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Step 14. How much was the revenue for the period in the dataset?"
    ]
   },
   {
@@ -484,28 +503,25 @@
    },
    "outputs": [
     {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "The revenue of the period was: $34500.16\n"
-     ]
+     "data": {
+      "text/plain": [
+       "34500.16000000046"
+      ]
+     },
+     "execution_count": 130,
+     "metadata": {},
+     "output_type": "execute_result"
     }
    ],
    "source": [
-    "# create a list of prices\n",
-    "prices = [float(value[1:-1]) for value in chipo.item_price] # strip the dollar sign and trailing space\n",
-    "\n",
-    "total = sum(prices) #sum the items\n",
-    "\n",
-    "\n",
-    "print(\"The revenue of the period was: \" + \"${0:.2f}\".format(total))"
+    "chipo.item_price.sum()"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 14. How many orders were made in the period?"
+    "### Step 15. How many orders were made in the period?"
    ]
   },
   {
@@ -527,15 +543,14 @@
     }
    ],
    "source": [
-    "orders = len((set([order for order in chipo.order_id])))\n",
-    "orders"
+    "chipo.order_id.value_counts().count()"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 15. What is the average amount per order?"
+    "### Step 16. What is the average amount per order?"
    ]
   },
   {
@@ -546,24 +561,30 @@
    },
    "outputs": [
     {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "The average order is: $18.81\n"
-     ]
+     "data": {
+      "text/plain": [
+       "18.811428571428689"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
     }
    ],
    "source": [
-    "avg_order = total / orders\n",
+    "order_grouped = chipo.groupby(by=['order_id']).sum()\n",
+    "order_grouped.mean()['item_price']\n",
+    "\n",
+    "# Or \n",
     "\n",
-    "print \"The average order is: $%s\" % round(avg_order, 2)"
+    "#chipo.groupby(by=['order_id']).sum().mean()['item_price']"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 16 How many different items are sold?"
+    "### Step 17. How many different items are sold?"
    ]
   },
   {
@@ -585,7 +606,7 @@
     }
    ],
    "source": [
-    "len(chipo.item_name.unique())"
+    "chipo.item_name.value_counts().count()"
    ]
   }
  ],
diff --git a/01_Getting_&_Knowing_Your_Data/Chipotle/Exercises.ipynb b/01_Getting_&_Knowing_Your_Data/Chipotle/Exercises.ipynb
index 3f4398901..4808ae47e 100644
--- a/01_Getting_&_Knowing_Your_Data/Chipotle/Exercises.ipynb
+++ b/01_Getting_&_Knowing_Your_Data/Chipotle/Exercises.ipynb
@@ -197,7 +197,23 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 13. How much was the revenue for the period in the dataset?"
+    "### Step 13. Turn the item price into a float"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Step 14. How much was the revenue for the period in the dataset?"
    ]
   },
   {
@@ -213,7 +229,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 14. How many orders were made in the period?"
+    "### Step 15. How many orders were made in the period?"
    ]
   },
   {
@@ -229,7 +245,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 15. What is the average amount per order?"
+    "### Step 16. What is the average amount per order?"
    ]
   },
   {
@@ -245,7 +261,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 16. How many different items are sold?"
+    "### Step 17. How many different items are sold?"
    ]
   },
   {
diff --git a/01_Getting_&_Knowing_Your_Data/Chipotle/Solutions.ipynb b/01_Getting_&_Knowing_Your_Data/Chipotle/Solutions.ipynb
index 7c37b2750..364eeb2cd 100644
--- a/01_Getting_&_Knowing_Your_Data/Chipotle/Solutions.ipynb
+++ b/01_Getting_&_Knowing_Your_Data/Chipotle/Solutions.ipynb
@@ -441,7 +441,23 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 13. How much was the revenue for the period in the dataset?"
+    "### Step 13. Turn the item price into a float"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Step 14. How much was the revenue for the period in the dataset?"
    ]
   },
   {
@@ -452,11 +468,14 @@
    },
    "outputs": [
     {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "The revenue of the period was: $34500.16\n"
-     ]
+     "data": {
+      "text/plain": [
+       "34500.16000000046"
+      ]
+     },
+     "execution_count": 130,
+     "metadata": {},
+     "output_type": "execute_result"
     }
    ],
    "source": []
@@ -465,7 +484,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 14. How many orders were made in the period?"
+    "### Step 15. How many orders were made in the period?"
    ]
   },
   {
@@ -492,7 +511,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 15. What is the average amount per order?"
+    "### Step 16. What is the average amount per order?"
    ]
   },
   {
@@ -503,11 +522,14 @@
    },
    "outputs": [
     {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "The average order is: $18.81\n"
-     ]
+     "data": {
+      "text/plain": [
+       "18.811428571428689"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
     }
    ],
    "source": []
@@ -516,7 +538,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "### Step 16 How many different items are sold?"
+    "### Step 17. How many different items are sold?"
    ]
   },
   {