Changed wording of task 4 and added notes about magic numbers in stub file and hint file. (#3930)

Author: BethanyG

exercises/concept/guidos-gorgeous-lasagna/.docs/hints.md

@@ -24,7 +24,8 @@
 
 - You need to define a [function][defining functions] with a single parameter representing the number of layers.
 - Use the [mathematical operator for multiplication][numbers] to multiply values.
-- You could define an extra _constant_ for the time in minutes per layer rather than using a "magic number" in your code.
+- You can define a PREPARATION_TIME _constant_ for the time in minutes per layer rather than using a ["magic
+  number"][magic-numbers] in your code.
 - This function should [return a value][return].
 
 ## 4. Calculate total elapsed cooking time (prep + bake) in minutes
@@ -43,6 +44,7 @@
 [constants]: https://stackoverflow.com/a/2682752
 [defining functions]: https://docs.python.org/3/tutorial/controlflow.html#defining-functions
 [docstrings]: https://docs.python.org/3/tutorial/controlflow.html#tut-docstrings
+[magic-numbers]: https://en.wikipedia.org/wiki/Magic_number_(programming)
 [naming]: https://realpython.com/python-variables/
 [numbers]: https://docs.python.org/3/tutorial/introduction.html#numbers
 [pep257]: https://www.python.org/dev/peps/pep-0257/

exercises/concept/guidos-gorgeous-lasagna/.docs/instructions.md

@@ -50,10 +50,16 @@ Assume each layer takes 2 minutes to prepare.
 ```
 
 
-## 4. Calculate total elapsed cooking time (prep + bake) in minutes
+## 4. Calculate total elapsed time (prepping + baking) in minutes
+
+Define the `elapsed_time_in_minutes()` function that takes two parameters as arguments:
+
+- `number_of_layers` (_the number of layers added to the lasagna_)
+- `elapsed_bake_time` (_the number of minutes the lasagna has spent baking in the oven already_).
+
+This function should return the total minutes you have been in the kitchen cooking — your preparation time layering +
+the time the lasagna has spent baking in the oven.
 
-Define the `elapsed_time_in_minutes()` function that takes two parameters as arguments: `number_of_layers` (_the number of layers added to the lasagna_) and `elapsed_bake_time` (_the number of minutes the lasagna has been baking in the oven_).
-This function should return the total number of minutes you have been cooking, or the sum of your preparation time and the time the lasagna has already spent baking in the oven.
 
 ```python
 >>> def elapsed_time_in_minutes(number_of_layers, elapsed_bake_time):

exercises/concept/guidos-gorgeous-lasagna/lasagna.py

@@ -8,7 +8,7 @@
 """
 
 
-#TODO: define the 'EXPECTED_BAKE_TIME' constant below.
+#TODO: define your EXPECTED_BAKE_TIME (required) and PREPARATION_TIME (optional) constants below.
 
 
 #TODO: Remove 'pass' and complete the 'bake_time_remaining()' function below.
@@ -27,9 +27,9 @@ def bake_time_remaining():
 
 
 #TODO: Define the 'preparation_time_in_minutes()' function below.
-# You might also consider defining a 'PREPARATION_TIME' constant.
+# To avoid the use of magic numbers (see: https://en.wikipedia.org/wiki/Magic_number_(programming)), you should define a PREPARATION_TIME constant.
 # You can do that on the line below the 'EXPECTED_BAKE_TIME' constant.
-# This will make it easier to do calculations.
+# This will make it easier to do calculations, and make changes to your code.