+information in memory and retrieving it later. Variables can be
+assigned to using the `<-` or `=` operator. For example, to assign the
+number `5` to the variable `foo`, you would write
+
+[[!sweavealike echo=1 results="hide" code="""
+foo <- 5
+"""]]
+
+Variables can retrieved simply by referring to them by name. For
+example, to add `8` to the variable `foo` and store the result in
+`bar`, you would do the following:
+
+[[!sweavealike echo=1 results="hide" code="""
+bar <- foo + 8
+"""]]
+