diff --git a/core/functions.ipynb b/core/functions.ipynb
index 39e14da..c86eb17 100644
--- a/core/functions.ipynb
+++ b/core/functions.ipynb
@@ -1,7 +1,7 @@
 {
  "metadata": {
   "name": "",
-  "signature": "sha256:93f08d982c73b7b50d2c679984dc25a00cc198f32a1a82269c2c119da5d0e26e"
+  "signature": "sha256:a37a234cd37895919493dabe7ab645bb2b5e24d9b304ab564e18b59eac4f7a0a"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -20,7 +20,7 @@
      "metadata": {},
      "source": [
       "* Functions as Objects\n",
-      "* Lambdas\n",
+      "* Lambda Functions\n",
       "* Closures\n",
       "* \\*args, \\*\\*kwargs\n",
       "* Currying\n",
@@ -157,6 +157,49 @@
       }
      ],
      "prompt_number": 3
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## Lambda Functions"
+     ]
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "Lambda functions are anonymous function and are convenient for data analysis, as data transformation functions take functions as arguments."
+     ]
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "Sort a sequence of strings by the number of letters"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "strings = ['foo', 'bar,', 'baz', 'f', 'fo', 'b', 'ba']\n",
+      "strings.sort(key=lambda x: len(list(x)))\n",
+      "strings"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "metadata": {},
+       "output_type": "pyout",
+       "prompt_number": 7,
+       "text": [
+        "['f', 'b', 'fo', 'ba', 'foo', 'baz', 'bar,']"
+       ]
+      }
+     ],
+     "prompt_number": 7
     }
    ],
    "metadata": {}