diff --git a/caesar/caesar.js b/caesar/caesar.js
index 42bc82b..f4d6a25 100644
--- a/caesar/caesar.js
+++ b/caesar/caesar.js
@@ -1,4 +1,4 @@
-var caesar = function() {
+const caesar = function() {
 
 }
 
diff --git a/caesar/caesar.spec.js b/caesar/caesar.spec.js
index 8f3468c..49fe254 100644
--- a/caesar/caesar.spec.js
+++ b/caesar/caesar.spec.js
@@ -1,4 +1,4 @@
-var caesar = require('./caesar')
+const caesar = require('./caesar')
 
 describe('caesar', function() {
   it('works with single letters', function() {
@@ -19,4 +19,7 @@ describe('caesar', function() {
   xit('works with large shift factors', function() {
     expect(caesar('Hello, World!', 75)).toEqual('Ebiil, Tloia!');
   });
+  xit('works with large negative shift factors', function() {
+    expect(caesar('Hello, World!', -29)).toEqual('Ebiil, Tloia!');
+  });
 });
diff --git a/calculator/calculator.spec.js b/calculator/calculator.spec.js
index 7a8bc3c..150a0aa 100644
--- a/calculator/calculator.spec.js
+++ b/calculator/calculator.spec.js
@@ -1,4 +1,4 @@
-var calculator = require ('./calculator.js');
+const calculator = require ('./calculator.js');
 
 describe('add', function() {
 	it('adds 0 and 0', function() {
diff --git a/fibonacci/fibonacci.js b/fibonacci/fibonacci.js
index 65b28bb..fd597f9 100644
--- a/fibonacci/fibonacci.js
+++ b/fibonacci/fibonacci.js
@@ -1,4 +1,4 @@
-var fibonacci = function() {
+const fibonacci = function() {
 
 }
 
diff --git a/fibonacci/fibonacci.spec.js b/fibonacci/fibonacci.spec.js
index 956e418..d7adebe 100644
--- a/fibonacci/fibonacci.spec.js
+++ b/fibonacci/fibonacci.spec.js
@@ -1,4 +1,4 @@
-var fibonacci = require('./fibonacci')
+const fibonacci = require('./fibonacci')
 
 describe('fibonacci', function() {
   it('works', function() {
diff --git a/generator-exercise/generators/app/templates/title.js b/generator-exercise/generators/app/templates/title.js
index baedf2c..34030c5 100644
--- a/generator-exercise/generators/app/templates/title.js
+++ b/generator-exercise/generators/app/templates/title.js
@@ -1,4 +1,4 @@
-var <%= title %> = function() {
+let <%= title %> = function() {
 
 }
 
diff --git a/generator-exercise/generators/app/templates/title.spec.js b/generator-exercise/generators/app/templates/title.spec.js
index 7db94cc..fa4ce97 100644
--- a/generator-exercise/generators/app/templates/title.spec.js
+++ b/generator-exercise/generators/app/templates/title.spec.js
@@ -1,4 +1,4 @@
-var <%= title %> = require('./<%=title%>')
+let <%= title %> = require('./<%=title%>')
 
 describe('<%=title%>', function() {
   it('EDITME', function() {
diff --git a/helloWorld/README.md b/helloWorld/README.md
index 2a51d18..cb5114c 100644
--- a/helloWorld/README.md
+++ b/helloWorld/README.md
@@ -10,7 +10,7 @@ This setup should be the same for all of the exercises.  The plain javascript fi
 
 Let's look at the spec file first:
 ```javascript
-var helloWorld = require('./helloWorld');
+const helloWorld = require('./helloWorld');
 
 describe('Hello World', function() {
     it('says hello world', function() {
@@ -26,7 +26,7 @@ For now you do not need to worry about how to write tests, but you should try to
 
 so let's look at the javascript file:
 ```javascript
-var helloWorld = function() {
+const helloWorld = function() {
   return ''
 }
 
@@ -40,7 +40,7 @@ Just to make sure, in case you're confused at this point, the test is telling yo
 
 this is what the final function should look like:
 ```javascript
-var helloWorld = function() {
+const helloWorld = function() {
   return 'Hello, World!'
 }
 
diff --git a/helloWorld/helloWorld.js b/helloWorld/helloWorld.js
index cf8cd75..a41264d 100644
--- a/helloWorld/helloWorld.js
+++ b/helloWorld/helloWorld.js
@@ -1,5 +1,5 @@
-var helloWorld = function() {
+const helloWorld = function() {
   return ''
 }
 
-module.exports = helloWorld
\ No newline at end of file
+module.exports = helloWorld
diff --git a/helloWorld/helloWorld.spec.js b/helloWorld/helloWorld.spec.js
index bb79262..c98e534 100644
--- a/helloWorld/helloWorld.spec.js
+++ b/helloWorld/helloWorld.spec.js
@@ -1,7 +1,7 @@
-var helloWorld = require('./helloWorld');
+const helloWorld = require('./helloWorld');
 
 describe('Hello World', function() {
   it('says hello world', function() {
     expect(helloWorld()).toEqual('Hello, World!');
   });
-});
\ No newline at end of file
+});
diff --git a/leapYears/README.md b/leapYears/README.md
index 30bf967..476febf 100644
--- a/leapYears/README.md
+++ b/leapYears/README.md
@@ -10,5 +10,5 @@ leapYears(1985) // is not a leap year: returns false
 ```
 
 
-## hints
+## Hints
 - use an `if` statement and `&&` to make sure all the conditions are met properly
diff --git a/leapYears/leapYears.js b/leapYears/leapYears.js
index 7884b78..ac786a2 100644
--- a/leapYears/leapYears.js
+++ b/leapYears/leapYears.js
@@ -1,4 +1,4 @@
-var leapYears = function() {
+const leapYears = function() {
 
 }
 
diff --git a/leapYears/leapYears.spec.js b/leapYears/leapYears.spec.js
index b58dadb..0d4d7d4 100644
--- a/leapYears/leapYears.spec.js
+++ b/leapYears/leapYears.spec.js
@@ -1,4 +1,4 @@
-var leapYears = require('./leapYears')
+const leapYears = require('./leapYears')
 
 describe('leapYears', function() {
   it('works with non century years', function() {
diff --git a/palindromes/palindromes.js b/palindromes/palindromes.js
index a27496d..ccfda4b 100644
--- a/palindromes/palindromes.js
+++ b/palindromes/palindromes.js
@@ -1,4 +1,4 @@
-var palindromes = function() {
+const palindromes = function() {
 
 }
 
diff --git a/palindromes/palindromes.spec.js b/palindromes/palindromes.spec.js
index e5e594d..1b24286 100644
--- a/palindromes/palindromes.spec.js
+++ b/palindromes/palindromes.spec.js
@@ -1,4 +1,4 @@
-var palindromes = require('./palindromes')
+const palindromes = require('./palindromes')
 
 describe('palindromes', function() {
   it('works with single words', function() {
diff --git a/pig_latin/pigLatin.spec.js b/pig_latin/pigLatin.spec.js
index 1eb4bfb..bbc8463 100644
--- a/pig_latin/pigLatin.spec.js
+++ b/pig_latin/pigLatin.spec.js
@@ -15,7 +15,7 @@
 
 // See https://en.wikipedia.org/wiki/Pig_Latin for more details.
 
-var pigLatin = require("./pigLatin.js");
+const pigLatin = require("./pigLatin.js");
 
 describe('#translate', function() {
 	it('translates a word beginning with a vowel', function() {
@@ -61,4 +61,4 @@ describe('#translate', function() {
 		s = pigLatin.translate("the quick brown fox");
 		expect(s).toEqual("ethay ickquay ownbray oxfay");
 	});
-});
\ No newline at end of file
+});
diff --git a/removeFromArray/README.md b/removeFromArray/README.md
index 9b3ebc0..44ee922 100644
--- a/removeFromArray/README.md
+++ b/removeFromArray/README.md
@@ -8,7 +8,7 @@ remove([1,2,3,4], 3) // should remove 3 and return [1,2,4]
 
 
 
-## hints
+## Hints
 the first test on this one is fairly easy, but there are a few things to think about(or google) here for the later tests:
 - how to remove a single element from an array
 - how to deal with multiple optional arguments in a javascript function
diff --git a/removeFromArray/removeFromArray.js b/removeFromArray/removeFromArray.js
index d36b8b1..11efd5c 100644
--- a/removeFromArray/removeFromArray.js
+++ b/removeFromArray/removeFromArray.js
@@ -1,4 +1,4 @@
-var removeFromArray = function() {
+const removeFromArray = function() {
 
 }
 
diff --git a/removeFromArray/removeFromArray.spec.js b/removeFromArray/removeFromArray.spec.js
index ff94e9a..28c744c 100644
--- a/removeFromArray/removeFromArray.spec.js
+++ b/removeFromArray/removeFromArray.spec.js
@@ -1,4 +1,4 @@
-var removeFromArray = require('./removeFromArray')
+const removeFromArray = require('./removeFromArray')
 
 describe('removeFromArray', function() {
   it('removes a single value', function() {
diff --git a/repeatString/README.md b/repeatString/README.md
index 85a0634..324744d 100644
--- a/repeatString/README.md
+++ b/repeatString/README.md
@@ -6,12 +6,13 @@ Write a function that simply repeats the string a given number of times:
 repeatString('hey', 3) // returns 'heyheyhey'
 ```
 
-You will notice in this exercise that there are multiple tests, after making the first one pass, enable the others one by one by deleting the x in front of the it() function.
+You will notice in this exercise that there are multiple tests (see in file `repeatString.spec.js`). Only the first test is currently enabled. So after making sure that this first one passes, enable the others one by one by deleting the `x` in front of the `it()` function.
 
 
-## hints
+## Hints
 
-You're going to want to use a loop for this one.
+- You're going to want to use a loop for this one.
 
-Create a variable to hold the string you're going to return, create a loop that repeats the given number of times and add the given string to the result on each loop.
+- Create a variable to hold the string you're going to return, create a loop that repeats the given number of times and add the given string to the result on each loop.
 
+- If running `jasmine tempConversion/tempConversion.spec.js` raises `Temporarily disabled with xit` errors, make sure you have enabled the rest of the tests (see above).
diff --git a/repeatString/repeatString.js b/repeatString/repeatString.js
index 49dfa90..770119a 100644
--- a/repeatString/repeatString.js
+++ b/repeatString/repeatString.js
@@ -1,4 +1,4 @@
-var repeatString = function() {
+const repeatString = function() {
 
 }
 
diff --git a/repeatString/repeatString.spec.js b/repeatString/repeatString.spec.js
index 3a33a3f..931b437 100644
--- a/repeatString/repeatString.spec.js
+++ b/repeatString/repeatString.spec.js
@@ -1,4 +1,4 @@
-var repeatString = require('./repeatString')
+const repeatString = require('./repeatString')
 
 describe('repeatString', function() {
   it('repeats the string', function() {
diff --git a/reverseString/README.md b/reverseString/README.md
index dfb00de..578adc1 100644
--- a/reverseString/README.md
+++ b/reverseString/README.md
@@ -11,5 +11,5 @@ You will notice in this exercise that there are multiple tests, after making the
 
 
 
-## hints
+## Hints
 Strings in JavaScript cannot be reversed directly so you're going to have to split it into something else first.. do the reversal and then join it back together into a string.
diff --git a/reverseString/reverseString.js b/reverseString/reverseString.js
index bca22be..febb577 100644
--- a/reverseString/reverseString.js
+++ b/reverseString/reverseString.js
@@ -1,5 +1,5 @@
-var reverseString = function() {
+const reverseString = function() {
 
 }
 
-module.exports = reverseString
\ No newline at end of file
+module.exports = reverseString
diff --git a/reverseString/reverseString.spec.js b/reverseString/reverseString.spec.js
index c61ed13..e48840c 100644
--- a/reverseString/reverseString.spec.js
+++ b/reverseString/reverseString.spec.js
@@ -1,4 +1,4 @@
-var reverseString = require('./reverseString')
+const reverseString = require('./reverseString')
 
 describe('reverseString', function() {
   it('reverses single word', function() {
@@ -12,4 +12,4 @@ describe('reverseString', function() {
   xit('works with numbers and punctuation', function() {
     expect(reverseString('123! abc!')).toEqual('!cba !321')
   })
-});
\ No newline at end of file
+});
diff --git a/snakeCase/snakeCase.js b/snakeCase/snakeCase.js
index d14f180..c948201 100644
--- a/snakeCase/snakeCase.js
+++ b/snakeCase/snakeCase.js
@@ -1,4 +1,4 @@
-var snakeCase = function() {
+const snakeCase = function() {
 
 }
 
diff --git a/snakeCase/snakeCase.spec.js b/snakeCase/snakeCase.spec.js
index 7664be0..cce17d2 100644
--- a/snakeCase/snakeCase.spec.js
+++ b/snakeCase/snakeCase.spec.js
@@ -1,4 +1,4 @@
-var snakeCase = require('./snakeCase')
+const snakeCase = require('./snakeCase')
 
 describe('snakeCase', function() {
   it('works with simple lowercased phrases', function() {
diff --git a/sumAll/README.md b/sumAll/README.md
index f399eda..64072a0 100644
--- a/sumAll/README.md
+++ b/sumAll/README.md
@@ -7,7 +7,7 @@ sumAll(1, 4) // returns the sum of 1 + 2 + 3 + 4 which is 10
 ```
 
 
-## hints
+## Hints
 
 Think about how you would do this on pen and paper and then how you might translate that process into code:
 - create a variable to hold the final sum
diff --git a/sumAll/sumAll.js b/sumAll/sumAll.js
index 863a79d..4030fe8 100644
--- a/sumAll/sumAll.js
+++ b/sumAll/sumAll.js
@@ -1,4 +1,4 @@
-var sumAll = function() {
+const sumAll = function() {
 
 }
 
diff --git a/sumAll/sumAll.spec.js b/sumAll/sumAll.spec.js
index 7f48e7a..520adc1 100644
--- a/sumAll/sumAll.spec.js
+++ b/sumAll/sumAll.spec.js
@@ -1,4 +1,4 @@
-var sumAll = require('./sumAll')
+const sumAll = require('./sumAll')
 
 describe('sumAll', function() {
   it('sums numbers within the range', function() {
diff --git a/tempConversion/README.md b/tempConversion/README.md
index 959d029..bd3954e 100644
--- a/tempConversion/README.md
+++ b/tempConversion/README.md
@@ -1,14 +1,17 @@
 # Exercise 06 - tempConversion
 
-This exercise asks you to create more than one function so the module.exports section of the spec file looks a little different this time.  Nothing to worry about, we're just packaging the functions into an object to be exported.
-
-Write two functions that convert temperatures from Fahrenheit to Celsius (and the other way around):
+Write two functions that convert temperatures from Fahrenheit to Celsius, and vice versa:
 ```
 ftoc(32) // fahrenheit to celsius, should return 0
 
 ctof(0) // celsius to fahrenheit, should return 32
 ```
 
+Because we are human, we want the result temperature to be rounded to one decimal place: i.e., `ftoc(100)` should return `37.8` and not `37.77777777777778`.
 
-## hints
-The math here is fairly straightforward.. just google the formula and implement it in the code
+This exercise asks you to create more than one function so the `module.exports` section of the spec file looks a little different this time.  Nothing to worry about, we're just packaging both functions into a single object to be exported.
+
+## Hints
+- You can find the relevant formulae on [Wikipedia](https://en.wikipedia.org/wiki/Conversion_of_units_of_temperature).
+
+- Try to find by yourself on the Internet how to round a number to 1 decimal place in JavaScript. If you struggle, have a look [here](https://stackoverflow.com/q/7342957/5433628).
diff --git a/tempConversion/tempConversion.js b/tempConversion/tempConversion.js
index 969c37e..4fa21ee 100644
--- a/tempConversion/tempConversion.js
+++ b/tempConversion/tempConversion.js
@@ -1,9 +1,9 @@
-var ftoc = function() {
-  
+const ftoc = function() {
+
 }
 
-var ctof = function() {
-  
+const ctof = function() {
+
 }
 
 module.exports = {
diff --git a/tempConversion/tempConversion.spec.js b/tempConversion/tempConversion.spec.js
index 6f69a7e..0dc9168 100644
--- a/tempConversion/tempConversion.spec.js
+++ b/tempConversion/tempConversion.spec.js
@@ -1,4 +1,4 @@
-var {ftoc, ctof} = require('./tempConversion')
+const {ftoc, ctof} = require('./tempConversion')
 
 describe('ftoc', function() {
   it('works', function() {