diff --git a/intermediate/01-high-level-computation-patterns.ipynb b/intermediate/01-high-level-computation-patterns.ipynb
index e5f17c1c..13c5f261 100644
--- a/intermediate/01-high-level-computation-patterns.ipynb
+++ b/intermediate/01-high-level-computation-patterns.ipynb
@@ -657,7 +657,7 @@
     ":class: dropdown\n",
     "\n",
     "```python\n",
-    "data.coarsen(lat=5, lon=5, boundary=\"trim\").reduce(np.mean).plot();\n",
+    "data.coarsen(lat=5, lon=5, boundary=\"trim\").reduce(np.ptp).plot();\n",
     "```\n",
     ":::\n",
     "::::"