Merge pull request freeCodeCamp#17 from bgroveben/beginner_math

Beginner Math Challenges added to challenge directory. Not added to challenges.json yet.

Author: Ethan-Arrowood

challenges/4.1.Addition/lesson.md

@@ -0,0 +1,15 @@
+## Python Addition
+
+In Python, an integer (int) is one of 3 distinct numeric types.  
+- https://docs.python.org/3.6/library/stdtypes.html#numeric-types-int-float-complex  
+
+In this exercise, you will add two integers using the plus (+) operator.
+- https://docs.python.org/3.6/library/operator.html#operator.add
+- https://docs.python.org/3/library/operator.html#mapping-operators-to-functions  
+```
+>>> 2 + 2
+4
+```
+
+**_Instructions:_**  
+**Change the 0 so that total will equal 20.**

challenges/4.1.Addition/lesson_code.py

@@ -0,0 +1,7 @@
+### Modify the code below ###
+
+total = 10 + 0
+
+### Modify the code above ###
+
+print(total)

challenges/4.1.Addition/lesson_tests.py

@@ -0,0 +1,12 @@
+import unittest
+import lesson_code
+
+class AdditionTests(unittest.TestCase):
+    def test_main(self):
+        total = lesson_code.total
+        self.assertIsInstance(total, int)
+        self.assertEqual(total, 20)
+
+# To run the tests from the console:
+# Make sure that you are in the '4.1.Addition' directory
+# ⇒  python3 -m unittest lesson_tests

challenges/4.2.Subtraction/lesson.md

@@ -0,0 +1,16 @@
+## Python Subtraction
+
+In Python, an integer (int) is one of 3 distinct numeric types.
+- https://docs.python.org/3.6/library/stdtypes.html#numeric-types-int-float-complex  
+
+In this exercise, you will subtract two integers using the minus (-) operator.
+- https://docs.python.org/3.6/library/operator.html#operator.sub
+- https://docs.python.org/3/library/operator.html#mapping-operators-to-functions
+
+```
+>>> 4 - 2
+2
+```
+
+**_Instructions:_**  
+**Change the 0 so that total will equal 10.**

challenges/4.2.Subtraction/lesson_code.py

@@ -0,0 +1,7 @@
+### Modify the code below ###
+
+total = 20 - 0
+
+### Modify the code above ###
+
+print(total)

challenges/4.2.Subtraction/lesson_tests.py

@@ -0,0 +1,12 @@
+import unittest
+import lesson_code
+
+class SubtractionTests(unittest.TestCase):
+    def test_main(self):
+        total = lesson_code.total
+        self.assertIsInstance(total, int)
+        self.assertEqual(total, 10)
+
+# To run the tests from the console:
+# Make sure that you are in the '4.2.Subtraction' directory
+# ⇒  python3 -m unittest lesson_tests

challenges/4.3.Multiplication/lesson.md

@@ -0,0 +1,16 @@
+## Python Multiplication
+
+Python uses the asterisk (\*) operator for multiplication.  
+If any or all of the numbers being multiplied are floating point numbers, then the product will be a float.
+- https://docs.python.org/3/library/operator.html#operator.mul
+- https://docs.python.org/3/library/operator.html#mapping-operators-to-functions
+- https://docs.python.org/3/library/stdtypes.html#numeric-types-int-float-complex
+```
+>>> 3 * 3
+9
+>>> 4.0 * 4
+16.0
+```
+
+**_Instructions:_**  
+**Change the 0 so that product will equal 80.**

challenges/4.3.Multiplication/lesson_code.py

@@ -0,0 +1,7 @@
+### Modify the code below ###
+
+product = 8 * 0
+
+### Modify the code above ###
+
+print(product)

challenges/4.3.Multiply/lesson_settings.json renamed to challenges/4.3.Multiplication/lesson_settings.json

@@ -0,0 +1,8 @@
+import unittest
+import lesson_code
+
+class MultiplicationTests(unittest.TestCase):
+    def test_main(self):
+        product = lesson_code.product
+        self.assertIsInstance(product, int)
+        self.assertEqual(product, 80)