Clarify "cardinality of" as "number of elements in" as many readers do
not have a math vocabulary.
diff --git a/Doc/library/sets.rst b/Doc/library/sets.rst
index 7bd2931..a7ae3ab 100644
--- a/Doc/library/sets.rst
+++ b/Doc/library/sets.rst
@@ -76,7 +76,8 @@
+-------------------------------+------------+---------------------------------+
| Operation | Equivalent | Result |
+===============================+============+=================================+
-| ``len(s)`` | | cardinality of set *s* |
+| ``len(s)`` | | number of elements in set *s*
+| | | (cardinality) |
+-------------------------------+------------+---------------------------------+
| ``x in s`` | | test *x* for membership in *s* |
+-------------------------------+------------+---------------------------------+