Improve clarity in tutorial introduction (GH-140669)

(cherry picked from commit cd4d0ae)

Co-authored-by: Thierry Martos <[email protected]>

Author: ThierryMT

Doc/tutorial/introduction.rst

@@ -49,7 +49,7 @@ primary prompt, ``>>>``.  (It shouldn't take long.)
 Numbers
 -------
 
-The interpreter acts as a simple calculator: you can type an expression at it
+The interpreter acts as a simple calculator: you can type an expression into it
 and it will write the value.  Expression syntax is straightforward: the
 operators ``+``, ``-``, ``*`` and ``/`` can be used to perform
 arithmetic; parentheses (``()``) can be used for grouping.