diff --git a/Work/bounce.py b/Work/bounce.py
index 3660ddd82..3cfd4ea1b 100644
--- a/Work/bounce.py
+++ b/Work/bounce.py
@@ -1,3 +1,8 @@
 # bounce.py
 #
 # Exercise 1.5
+
+height = 100
+for i in range(10):
+    height = height * 3 / 5
+    print(round(height,4))
diff --git a/Work/learnings.md b/Work/learnings.md
new file mode 100644
index 000000000..91b50500a
--- /dev/null
+++ b/Work/learnings.md
@@ -0,0 +1,29 @@
+# Learnings
+
+These are certain *miscellaneous* notes on python. The aim is not to capture everything learned in the course, but to note down certain curious aspects that I wouldn't notice or remember otherwise.
+
+## if...elif
+
+Like bash, python uses `elif`, not `else if`.
+
+```python
+if a > 10:
+    print("big")
+elif a < 5:
+    print("not so")
+else:
+    pass
+```
+
+## division, integer division
+
+python (atleast recent versions) divides numbers correctly and produces floats even when dividing integers. `10/3` produces `3.33333`. Unlike in some other languages, we don't have to pass it as `10.0/3` to get the correct result. This makes sense since a dynamically typed language like python should be transparent about the number types. It's justified if a statically typed language returns a rounded (floored) int as a result of division, and the developer is responsible to know that, but not in a dynamically typed language.
+
+That said, python also has a *Floor Divide* operator `//`
+
+```
+>>> 10/3
+3.3333333333333335
+>>> 10//3
+3
+```
diff --git a/Work/mortgage.py b/Work/mortgage.py
index d527314e3..0faa1c997 100644
--- a/Work/mortgage.py
+++ b/Work/mortgage.py
@@ -1,3 +1,37 @@
 # mortgage.py
 #
-# Exercise 1.7
+# Exercise 1.11
+
+principal = 500_000.0
+rate = 0.05
+regular_payment = 2684.11
+
+# months are counted from 1, i.e., the first payment happens in month 1
+extra_payment_start_month = 60  # inclusive
+extra_payment_end_month = 108   # also inclusive. but why?
+extra_payment = 1000
+total_paid = 0.0
+
+# this still has to count from zero
+months = 0
+while principal > 0:
+    # We increment months at the beginning so the logic looks natural.
+    # Think that the month has arrived, then we proceed with payment. 
+    months = months + 1
+    principal = principal * (1+rate/12)
+
+    if months >= extra_payment_start_month and months <= extra_payment_end_month:
+        payment = regular_payment + extra_payment
+    else:
+        payment = regular_payment
+    
+    if principal < payment:
+        payment = principal
+
+    principal = principal - payment
+    total_paid = total_paid + payment
+
+    print(months, round(total_paid, 2), round(principal,2))
+
+print('Total paid', total_paid)
+print('Months', months)
diff --git a/Work/pcost.py b/Work/pcost.py
index e68aa20b4..3f3378639 100644
--- a/Work/pcost.py
+++ b/Work/pcost.py
@@ -1,3 +1,13 @@
 # pcost.py
 #
 # Exercise 1.27
+
+f = open('Data/portfolio.csv', 'rt')
+headers = next(f)
+
+total_cost = 0
+for line in f:
+    row = line.strip().split(',')
+    total_cost = total_cost + int(row[1]) * float(row[2])
+
+print('Cost of the portfolio is ', total_cost)
diff --git a/Work/sears.py b/Work/sears.py
new file mode 100644
index 000000000..ee061ae6c
--- /dev/null
+++ b/Work/sears.py
@@ -0,0 +1,13 @@
+bill_thickness = 0.11 * 0.001    # Meters (0.11 mm)
+sears_height   = 442             # Height (meters)
+num_bills      = 1
+day            = 1
+
+while num_bills * bill_thickness < sears_height:
+    print(day, num_bills, num_bills * bill_thickness)
+    day = day + 1
+    num_bills = num_bills * 2
+
+print('Number of days', day)
+print('Number of bills', num_bills)
+print('Final height', num_bills * bill_thickness)
diff --git a/Work/unicode.py b/Work/unicode.py
new file mode 100644
index 000000000..1d9e496b9
--- /dev/null
+++ b/Work/unicode.py
@@ -0,0 +1,13 @@
+# In python 3 all strings are unicode.
+# We can enter not-easily-typable unicode chars in a variety of ways 
+print('Using unicode chars in python')
+print('* Use slash-u followed by unicode number/code')
+print('\t', '\\u0101 =>', '\u0101')
+print('\t', 'S\\u0101dhakam =>', 'S\u0101dhakam')
+print('\t', '\\u00bd =>', '\u00bd')
+print('\t', 'or, \\xbd =>', '\xbd')
+print()
+print("* Use the charactor's name with \\N")
+print('\t', "\\N{TAMIL FRACTION ONE QUARTER} =>", "\N{TAMIL FRACTION ONE QUARTER}")
+print('\t', "\\N{VULGAR FRACTION ONE HALF} =>", "\N{VULGAR FRACTION ONE HALF}")
+