diff --git a/math_linear_algebra.ipynb b/math_linear_algebra.ipynb
index df6e95a..7d8f8cb 100644
--- a/math_linear_algebra.ipynb
+++ b/math_linear_algebra.ipynb
@@ -2662,7 +2662,7 @@
     "editable": true
    },
    "source": [
-    "Now let's look at the dot product $P \\cdot U$:"
+    "Now let's look at the dot product $U \\cdot P$:"
    ]
   },
   {
@@ -4047,7 +4047,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.5.3"
+   "version": "3.5.2"
   },
   "toc": {
    "toc_cell": false,