diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..be87f0d6f 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1,4 @@
 console.log("Hello world");
+console.log("Hello world. I just started learning JS!")
+console.log("This is the first exercise in the module.")
+console.log("The module takes 3 weeks.")
\ No newline at end of file
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..7beea3261 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `greeting`
-
+var greeting = "Hello world";
+console.log(greeting);
+console.log(greeting);
 console.log(greeting);
diff --git a/exercises/D-strings/exercise.js b/exercises/D-strings/exercise.js
index 2cffa6a81..9a78510f5 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
+var message = "This is a string";
+var messageType = typeof message;
 console.log(message);
+console.log(messageType);
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..3e06e9327 100644
--- a/exercises/E-strings-concatenation/exercise.js
+++ b/exercises/E-strings-concatenation/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
-console.log(message);
+var greetingStart = "Hi, my name is ";
+var name = "Michael";
+var greeting = greetingStart + name;
+console.log(greeting);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..6c778d099 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `message`
-
+var name = "Michael";
+var nameLength = name.length;
+var message = "My name is " + name + " and my name is " + nameLength +" characters long.";
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..38dd783bb 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,5 @@
 const name = " Daniel  ";
-
+var trimmedName = name.trim();
+var nameLength = name.length;
+var message="My name is " + trimmedName + " and  my name is " + nameLength + " characters long."
 console.log(message);
diff --git a/exercises/G-numbers/exercise.js b/exercises/G-numbers/exercise.js
index 49e7bc00b..6c098af33 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,8 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+var numberOfStudents = 15;
+var numberOfMentors = 6;
+var numberOfParticipants = numberOfStudents + numberOfMentors;
+// Output
+console.log("Number of students: " + numberOfStudents);
+console.log("Number of mentors: " + numberOfMentors);
+console.log("Total number of students and mentors: " + numberOfParticipants);
\ No newline at end of file
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..26dc4a7ff 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,10 @@
+// Declare and initialise variables
 var numberOfStudents = 15;
 var numberOfMentors = 8;
+var numberOfParticipants = numberOfStudents + numberOfMentors;
+var percentageOfStudents = Math.round(numberOfStudents / numberOfParticipants * 100);
+var percentageOfMentors = Math.round(numberOfMentors / numberOfParticipants * 100);
+// Output
+console.log("Percentage of students: " + percentageOfStudents + "%");
+console.log("Percentage of mentors: " + percentageOfMentors + "%");
+
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..ea8cacb47 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,15 @@
 function halve(number) {
   // complete the function here
+    return number / 2;
 }
 
 var result = halve(12);
+console.log(result);
+
+result = halve(23);
+console.log(result);
 
+result = halve(56);
 console.log(result);
+
+
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..606ed7533 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,7 +1,13 @@
 function triple(number) {
   // complete function here
+    return number * 3;
 }
 
 var result = triple(12);
+console.log(result);
+
+result = triple(23);
+console.log(result);
 
+result = triple(56);
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..8a48c7959 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,6 +1,7 @@
 // Complete the function so that it takes input parameters
-function multiply() {
+function multiply(a,b) {
   // Calculate the result of the function and return it
+    return a * b;
 }
 
 // Assign the result of calling the function the variable `result`
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..6839e8684 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,5 +1,7 @@
 // Declare your function first
-
+function divide(a, b) {
+    return a / b;
+}
 var result = divide(3, 4);
 
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise3.js b/exercises/K-functions-parameters/exercise3.js
index 537e9f4ec..dabc803a2 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,7 @@
 // Write your function here
-
+function createGreeting(name) {    
+    return "Hello, my name is " + name;
+}
 var greeting = createGreeting("Daniel");
 
 console.log(greeting);
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..a224196b4 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,7 @@
 // Declare your function first
-
+function add(a, b) {
+    return a + b;
+}
 // Call the function and assign to a variable `sum`
-
+var sum = add(13, 124);
 console.log(sum);
diff --git a/exercises/K-functions-parameters/exercise5.js b/exercises/K-functions-parameters/exercise5.js
index 7c5bcd605..fa64315fb 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,5 +1,7 @@
 // Declare your function here
-
+function createLongGreeting(name, age) {
+    return "Hello, my name is " + name + " and I'm " + age + " years old";
+}
 const greeting = createLongGreeting("Daniel", 30);
 
 console.log(greeting);
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..7dc8249c2 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -1,5 +1,25 @@
-var mentor1 = "Daniel";
-var mentor2 = "Irina";
-var mentor3 = "Mimi";
-var mentor4 = "Rob";
-var mentor5 = "Yohannes";
+// Declare and initialise global variables
+var numberOfStudents = 15;
+var numberOfMentors = 8;
+var numberOfParticipants = numberOfStudents + numberOfMentors;
+var result; // percentage calculation result
+var message;    // message to be displayed 
+
+// This function calculates percentages
+function calculatePercentage(a, b) {
+    return Math.round(a / b * 100); // approximate value
+}
+
+// Function to display the result of percentage calculation
+function displayResult(val, desc) { // val = percentage value, desc = what the percentage is for
+    var message = "Percentage of ".concat(desc+": ", val + "%");
+    console.log(message);
+}
+
+// About students
+result = calculatePercentage(numberOfStudents, numberOfParticipants);
+message = displayResult(result, "students");
+
+// About mentors
+result = calculatePercentage(numberOfMentors, numberOfParticipants);
+message = displayResult(result, "mentors");
diff --git a/exercises/L-functions-nested/exercise2.js b/exercises/L-functions-nested/exercise2.js
new file mode 100644
index 000000000..6c0139b8d
--- /dev/null
+++ b/exercises/L-functions-nested/exercise2.js
@@ -0,0 +1,23 @@
+var mentor1 = "Daniel";
+var mentor2 = "Irina";
+var mentor3 = "Mimi";
+var mentor4 = "Rob";
+var mentor5 = "Yohannes";
+
+// Function to change style of text to uppercase
+function changeToUpperCase(text) {
+    return text.toUpperCase();
+}
+
+// Function to display greeting message, given name of a person to greet
+function greetSomeone(name) {
+    var greeting = "Hello " + name;
+    var message = changeToUpperCase(greeting);
+    console.log(message);
+}
+
+greetSomeone(mentor1);
+greetSomeone(mentor2);
+greetSomeone(mentor3);
+greetSomeone(mentor4);
+greetSomeone(mentor5);
\ No newline at end of file
diff --git a/extra/1-currency-conversion.js b/extra/1-currency-conversion.js
index 70a2fe863..f04fd3050 100644
--- a/extra/1-currency-conversion.js
+++ b/extra/1-currency-conversion.js
@@ -5,7 +5,9 @@
   Write a function that converts a price to USD (exchange rate is 1.4 $ to £)
 */
 
-function convertToUSD() {}
+function convertToUSD(price) {
+    return price * 1.4;
+}
 
 /*
   CURRENCY FORMATTING
@@ -15,7 +17,13 @@ function convertToUSD() {}
   They have also decided that they should add a 1% fee to all foreign transactions, which means you only convert 99% of the £ to BRL.
 */
 
-function convertToBRL() {}
+function convertToBRL(price) {
+    const exchangeRate = 5.7;
+    const serviceCharge = 0.01 * price;
+    let actualPrice = price - serviceCharge;
+    let priceInBrl = actualPrice * exchangeRate;
+    return priceInBrl;
+}
 
 /* ======= TESTS - DO NOT MODIFY ===== 
 There are some Tests in this file that will help you work out if your code is working.
diff --git a/extra/2-piping.js b/extra/2-piping.js
index 067dd0f5b..063f5cc7d 100644
--- a/extra/2-piping.js
+++ b/extra/2-piping.js
@@ -16,26 +16,28 @@
   the final result to the variable goodCode
 */
 
-function add() {
-
+function add(a,b) {
+    return a + b;
 }
 
-function multiply() {
-
+function multiply(a,b) {
+    return a * b;
 }
 
-function format() {
-
+function format(num) {
+    return "£" + num;
 }
 
 const startingValue = 2
 
 // Why can this code be seen as bad practice? Comment your answer.
-let badCode = 
+let badCode = format(multiply(2, add(10, startingValue)));
 
 /* BETTER PRACTICE */
 
-let goodCode = 
+let goodCode = add(10, startingValue);
+goodCode = multiply(goodCode, 2);
+goodCode = format(goodCode);
 
 /* ======= TESTS - DO NOT MODIFY ===== 
 There are some Tests in this file that will help you work out if your code is working.
diff --git a/extra/3-magic-8-ball.js b/extra/3-magic-8-ball.js
index e32182cfe..2e0c9face 100644
--- a/extra/3-magic-8-ball.js
+++ b/extra/3-magic-8-ball.js
@@ -47,6 +47,34 @@
 // and return the answer.
 function shakeBall() {
   //Write your code in here
+    console.log("The ball has shaken!");
+
+    let answers = [
+        "It is certain.",
+        "It is decidedly so.",
+        "Without a doubt.",
+        "Yes - definitely.",
+        "You may rely on it.",
+        "As I see it, yes.",
+        "Most likely.",
+        "Outlook good.",
+        "Yes.",
+        "Signs point to yes.",
+        "Reply hazy, try again.",
+        "Ask again later.",
+        "Better not tell you now.",
+        "Cannot predict now.",
+        "Concentrate and ask again.",
+        "Don't count on it.",
+        "My reply is no.",
+        "My sources say no.",
+        "Outlook not so good.",
+        "Very doubtful."
+    ];
+    // Select a random answer from list
+    let index = Math.floor(Math.random() * answers.length);
+    let randomAnswer = answers[index];
+   return randomAnswer;
 }
 
 /* 
@@ -60,6 +88,44 @@ function shakeBall() {
 */
 function checkAnswer(answer) {
   //Write your code in here
+    let answers = [
+        "very positive",
+        "positive",
+        "negative",
+        "very negative"
+    ];
+
+    switch (answer) {
+        case "It is certain.":
+        case "It is decidedly so.":
+        case "Without a doubt.":
+        case "Yes - definitely.":
+        case "You may rely on it.":
+            answer = answers[0];
+            break; 
+        case "As I see it, yes.":
+        case "Most likely.":
+        case "Outlook good.":
+        case "Yes.":
+        case "Signs point to yes.":
+            answer = answers[1];
+            break;
+        case "Reply hazy, try again.":
+        case "Ask again later.":
+        case "Better not tell you now.":
+        case "Cannot predict now.":
+        case "Concentrate and ask again.":
+            answer = answers[2];
+            break;
+        case "Don't count on it.":
+        case "My reply is no.":
+        case "My sources say no.":
+        case "Outlook not so good.":
+        case "Very doubtful.":
+            answer = answers[3];
+            break;
+    }
+    return answer;
 }
 
 /* 
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index 0a21afd1b..6f498d235 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,16 +1,17 @@
 // There are syntax errors in this code - can you fix it to pass the tests?
 
-function addNumbers(a b c) {
+function addNumbers(a, b, c) {
     return a + b + c;
 }
 
-function introduceMe(name, age)
-return "Hello, my name is " + name "and I am " age + "years old";
+function introduceMe(name, age) {
+    return "Hello, my name is " + name + " and I am " + age + " years old";
+}
 
 function getTotal(a, b) {
-    total = a ++ b;
+    total = a + b;
 
-    return "The total is total"
+    return "The total is " + total;
 }
 
 /* 
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 3c578ad87..d17aed27e 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,18 +1,18 @@
 // The syntax for this function is valid but it has an error, find it and fix it.
 
 function trimWord(word) {
-  return wordtrim();
+  return word.trim();
 }
 
 function getWordLength(word) {
-  return "word".length();
+    return word.length;
 }
 
-function multiply(a, b, c) {
-  a * b * c;
-  return;
+function multiply(a, b, c) {  
+  return a * b * c;
 }
 
+const { stringify } = require("querystring");
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====
diff --git a/mandatory/3-function-output.js b/mandatory/3-function-output.js
index c9221a200..2939f188a 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,16 +1,18 @@
-// Add comments to explain what this function does. You're meant to use Google!
+// Return a random number multiplied by 10
 function getNumber() {
   return Math.random() * 10;
 }
 
-// Add comments to explain what this function does. You're meant to use Google!
+// Affix one string value to the end of a second string value and return the merge
 function s(w1, w2) {
+    
   return w1.concat(w2);
 }
 
 function concatenate(firstWord, secondWord, thirdWord) {
   // Write the body of this function to concatenate three words together.
   // Look at the test case below to understand what this function is expected to return.
+    return firstWord.concat(" ", secondWord, " ", thirdWord);
 }
 
 /* 
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index c9e41c691..ca0d4c3a4 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,7 +5,14 @@
   Sales tax is 20% of the price of the product
 */
 
-function calculateSalesTax() {}
+/***** Quick Note *******
+ * The function below fails the tests. However, it meets the requirements (lines 4 and 5) 
+ * and has no logic errors (I hope).
+ * I hope the suggestion I made (starts at line 35) can explain why. */
+
+function calculateSalesTax(price) {
+    return price / 5;   // tax = 20% of price
+}
 
 /*
   CURRENCY FORMATTING
@@ -17,8 +24,23 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(price) {
+    let tax = calculateSalesTax(price);
+    let actualPrice = price + tax;
+    return "£" + actualPrice.toFixed(2);
+}
+
+/*
+ ========================= THIS IS A SUGGESTION ============================
+ * I suggest calls made to the function calculateSalesTax (lines 70 through 72) be 
+ * edited for values: calculateSalesTax() should return the tax (i.e. 20% of product
+ * price, as stipulated in lines 4 and 5 above), not the value of price + tax. 
+ * 
+ * It's possible to make calculateSalesTax() calculate the total price to pass the tests,
+ * but that does seem counterintuitive to what we expect the function does.
+ ============================================================================ */
 
+const { format } = require("path");
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====