diff --git a/exercises/B-hello-world/exercise.js b/exercises/B-hello-world/exercise.js
index b179ee953..4bbda6b3c 100644
--- a/exercises/B-hello-world/exercise.js
+++ b/exercises/B-hello-world/exercise.js
@@ -1 +1,5 @@
 console.log("Hello world");
+console.log("Hello world. I just started learning JavaScript.");
+console.log("My name is Amarachi. I am a Code Your Future Trainee.")
+console.log("I am happy");
+console.log(2);
diff --git a/exercises/C-variables/exercise.js b/exercises/C-variables/exercise.js
index a6bbb9786..a17507f15 100644
--- a/exercises/C-variables/exercise.js
+++ b/exercises/C-variables/exercise.js
@@ -1,3 +1,5 @@
 // Start by creating a variable `greeting`
-
+let 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..af2bb4d3c 100644
--- a/exercises/D-strings/exercise.js
+++ b/exercises/D-strings/exercise.js
@@ -1,3 +1,4 @@
 // Start by creating a variable `message`
-
+let message = "This is a string."
 console.log(message);
+console.log(typeof (message));
diff --git a/exercises/E-strings-concatenation/exercise.js b/exercises/E-strings-concatenation/exercise.js
index 2cffa6a81..59304d39a 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`
-
+const greeting = " Hello, my name is ";
+const myName = "Amarachi";
+const message = greeting + myName;
 console.log(message);
diff --git a/exercises/F-strings-methods/exercise.js b/exercises/F-strings-methods/exercise.js
index 2cffa6a81..ed9a93f9d 100644
--- a/exercises/F-strings-methods/exercise.js
+++ b/exercises/F-strings-methods/exercise.js
@@ -1,3 +1,15 @@
 // Start by creating a variable `message`
-
-console.log(message);
+// let myName = "Amarachi";
+// myName = myName.length;
+// console.log(myName);
+//  let myMessage = "My name is ";
+//  let myName = "Amarachi";
+//  let secondMessage = " and my name is ";
+//  let nameLength = myName.length;
+//  let thirdMessage = " characters long"
+//  let message = myMessage + myName + secondMessage + nameLength + thirdMessage;
+//  console.log(message);
+ let myName = "Amarachi";
+ let nameLength = myName.length;
+ let message = `My name is ${myName} and my name is ${nameLength} characters long`;
+ console.log(message);
\ No newline at end of file
diff --git a/exercises/F-strings-methods/exercise2.js b/exercises/F-strings-methods/exercise2.js
index b4b46943d..fd4ed0cdb 100644
--- a/exercises/F-strings-methods/exercise2.js
+++ b/exercises/F-strings-methods/exercise2.js
@@ -1,3 +1,6 @@
 const name = " Daniel  ";
+const nameTrim = name.trim();
+const nameLength = nameTrim.length;
+const message = `My name is ${nameTrim} 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..3d027cd3f 100644
--- a/exercises/G-numbers/exercise.js
+++ b/exercises/G-numbers/exercise.js
@@ -1 +1,5 @@
 // Start by creating a variables `numberOfStudents` and `numberOfMentors`
+let numberOfStudents = 20;
+let numberOfMentors = 13;
+let totalNumber = numberOfStudents + numberOfMentors;
+console.log(totalNumber);
\ No newline at end of file
diff --git a/exercises/I-floats/exercise.js b/exercises/I-floats/exercise.js
index a5bbcd852..f95e282a6 100644
--- a/exercises/I-floats/exercise.js
+++ b/exercises/I-floats/exercise.js
@@ -1,2 +1,11 @@
-var numberOfStudents = 15;
-var numberOfMentors = 8;
+// var numberOfStudents = 15;
+// var numberOfMentors = 8;
+// var totalNumber = numberOfStudents + numberOfMentors;
+// var percentStudents = numberOfStudents * 100 / totalNumber;
+// console.log(Math.round(percentStudents));
+
+let numberOfStudents = 15;
+let numberOfMentors = 8;
+let totalNumber = numberOfStudents + numberOfMentors;
+let percentMentors = (numberOfMentors * 100) / totalNumber;
+console.log(Math.round(percentMentors));
diff --git a/exercises/J-functions/exercise.js b/exercises/J-functions/exercise.js
index 0ae5850e5..89d5f4290 100644
--- a/exercises/J-functions/exercise.js
+++ b/exercises/J-functions/exercise.js
@@ -1,7 +1,8 @@
 function halve(number) {
   // complete the function here
+  return number / 2;
 }
 
-var result = halve(12);
+let result = halve(12);
 
 console.log(result);
diff --git a/exercises/J-functions/exercise2.js b/exercises/J-functions/exercise2.js
index 82ef5e780..db0a8b857 100644
--- a/exercises/J-functions/exercise2.js
+++ b/exercises/J-functions/exercise2.js
@@ -1,7 +1,8 @@
 function triple(number) {
   // complete function here
+  return number * 3;
 }
 
-var result = triple(12);
+let result = triple(12);
 
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise.js b/exercises/K-functions-parameters/exercise.js
index 8d5db5e69..d96efd1a8 100644
--- a/exercises/K-functions-parameters/exercise.js
+++ b/exercises/K-functions-parameters/exercise.js
@@ -1,9 +1,10 @@
 // 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`
-var result = multiply(3, 4);
+let result = multiply(3, 4);
 
 console.log(result);
diff --git a/exercises/K-functions-parameters/exercise2.js b/exercises/K-functions-parameters/exercise2.js
index db7a8904b..97f4b4b88 100644
--- a/exercises/K-functions-parameters/exercise2.js
+++ b/exercises/K-functions-parameters/exercise2.js
@@ -1,5 +1,8 @@
 // Declare your function first
+function divide(a, b) {
+    return a / b;
+}
 
-var result = divide(3, 4);
+let 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..9d217b843 100644
--- a/exercises/K-functions-parameters/exercise3.js
+++ b/exercises/K-functions-parameters/exercise3.js
@@ -1,5 +1,7 @@
 // Write your function here
-
-var greeting = createGreeting("Daniel");
+function createGreeting(string) {
+    return ("Hello, my name is " + string);
+}
+let greeting = createGreeting("Daniel");
 
 console.log(greeting);
diff --git a/exercises/K-functions-parameters/exercise4.js b/exercises/K-functions-parameters/exercise4.js
index 7ab44589e..0ab8d5ac9 100644
--- a/exercises/K-functions-parameters/exercise4.js
+++ b/exercises/K-functions-parameters/exercise4.js
@@ -1,5 +1,8 @@
 // Declare your function first
-
+function add(a, b) {
+    return a + b;
+}
 // Call the function and assign to a variable `sum`
+let 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..20b599547 100644
--- a/exercises/K-functions-parameters/exercise5.js
+++ b/exercises/K-functions-parameters/exercise5.js
@@ -1,4 +1,7 @@
 // Declare your function here
+function createLongGreeting(name, num) {
+    return ("Hello, my name is " + name + " and I'm " + num + " years old");
+}
 
 const greeting = createLongGreeting("Daniel", 30);
 
diff --git a/exercises/L-functions-nested/exercise.js b/exercises/L-functions-nested/exercise.js
index a5d377442..03db43f13 100644
--- a/exercises/L-functions-nested/exercise.js
+++ b/exercises/L-functions-nested/exercise.js
@@ -1,5 +1,23 @@
-var mentor1 = "Daniel";
-var mentor2 = "Irina";
-var mentor3 = "Mimi";
-var mentor4 = "Rob";
-var mentor5 = "Yohannes";
+// var mentor1 = "Daniel";
+// var mentor2 = "Irina";
+// var mentor3 = "Mimi";
+// var mentor4 = "Rob";
+// var mentor5 = "Yohannes";
+function shoutyGreeting(name) {
+    return ("Hello " + name);
+}
+let mentor1 = shoutyGreeting("Daniel");
+console.log(mentor1.toUpperCase());
+
+let mentor2 = shoutyGreeting("Irina");
+console.log(mentor2.toUpperCase());
+
+let mentor3 = shoutyGreeting("Mimi");
+console.log(mentor3.toUpperCase());
+
+let mentor4 = shoutyGreeting("Rob");
+console.log(mentor4.toUpperCase());
+
+let mentor5 = shoutyGreeting("Yohannes");
+console.log(mentor5.toUpperCase());
+
diff --git a/extra/1-currency-conversion.js b/extra/1-currency-conversion.js
index 75b3c6aab..258067f49 100644
--- a/extra/1-currency-conversion.js
+++ b/extra/1-currency-conversion.js
@@ -5,7 +5,15 @@
   Write a function that converts a price to USD (exchange rate is 1.4 $ to £)
 */
 
-function convertToUSD() {}
+function convertToUSD(number) {
+  return number * 1.4;
+
+}
+let myNum = convertToUSD(32);
+console.log(myNum);
+
+myNum = convertToUSD(50);
+console.log(myNum);
 
 /*
   CURRENCY CONVERSION
@@ -15,12 +23,20 @@ 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(number) {
+  return parseFloat(((number * 99 / 100) * 5.7).toFixed(2));
+}
+
+let myConvert = convertToBRL(30);
+console.log(myConvert);
+
+myConvert = convertToBRL(1.5);
+console.log(myConvert);
 
 /* ======= TESTS - DO NOT MODIFY ===== 
 There are some Tests in this file that will help you work out if your code is working.
 
-To run the tests for just this one file, type `npm test -- --testPathPattern 1-currency-conversion` into your terminal
+To run the tests for just this one file, type `` into your terminal
 (Reminder: You must have run `npm install` one time before this will work!)
 */
 
diff --git a/extra/2-piping.js b/extra/2-piping.js
index b4f8c4c1b..6bd5aa300 100644
--- a/extra/2-piping.js
+++ b/extra/2-piping.js
@@ -16,26 +16,47 @@
   the final result to the variable goodCode
 */
 
-function add() {
+function add(a, b) {
+  return a + b;
 
 }
 
-function multiply() {
+let num = add(1, 3);
+console.log(num);
+
+num = add(2.4, 5);
+console.log(num);
+
+function multiply(a, b) {
+  return a * b;
 
 }
 
-function format() {
+let myNum = multiply(2, 3);
+console.log(myNum);
 
+function format(number) {
+  return `£${number}`;
 }
 
+let myInt = format(16);
+console.log(myInt);
+
+myInt = format(10.1);
+console.log(myInt);
+
 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))); // Because it is difficult to read.
 
 /* BETTER PRACTICE */
+let addBetter = add(10, startingValue);
+let multiplyBetter = multiply(2, addBetter);
+let formatBetter = format(multiplyBetter);
 
-let goodCode =
+let goodCode = formatBetter;
+console.log(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 46f65f928..d82376262 100644
--- a/extra/3-magic-8-ball.js
+++ b/extra/3-magic-8-ball.js
@@ -14,12 +14,13 @@
 
   Below are the possible answers:
 
-  ## Very positive
+  ## Very positive
     It is certain.
     It is decidedly so.
     Without a doubt.
     Yes - definitely.
     You may rely on it.
+    
 
   ## Positive
     As I see it, yes.
@@ -42,13 +43,42 @@
     Outlook not so good.
     Very doubtful.
 */
-
+ const veryPositive = [
+  "It is certain.",
+  "It is decidedly so.",
+  "Without a doubt.",
+  "Yes - definitely.",
+  "You may rely on it.",
+];
+
+const positive = [
+  'As I see it, yes.',
+  'Most likely.',
+  'Outlook good.',
+  'Yes.',
+  'Signs point to yes.',];
+    
+const negative = ['Reply hazy, try again.',
+  'Ask again later.',
+  'Better not tell you now.',
+  'Cannot predict now.',
+  'Concentrate and ask again.',];
+
+const veryNegative = ['Don\'t count on it.',
+  'My reply is no.',
+  'My sources say no.',
+  'Outlook not so good.',
+  'Very doubtful.',];
+
+const myAnswer = [...veryPositive, ...positive, ...negative, ...veryNegative,];
 // This should log "The ball has shaken!"
 // and return the answer.
 function shakeBall() {
   //Write your code in here
-}
+  console.log("The ball has shaken!");
 
+  return myAnswer[Math.round(Math.random() * myAnswer.length)];
+}
 /* 
   This function should say whether the answer it is given is
     - very positive
@@ -101,7 +131,9 @@ test("magic 8 ball returns different values each time", () => {
     );
   }
 
-  let seenPositivities = new Set(Array.from(seenAnswers.values()).map(checkAnswer));
+  let seenPositivities = new Set(
+    Array.from(seenAnswers.values()).map(checkAnswer)
+  );
   if (seenPositivities.size < 2) {
     throw Error(
       "Expected to random answers with different positivities each time shakeBall was called, but always got the same one"
diff --git a/mandatory/1-syntax-errors.js b/mandatory/1-syntax-errors.js
index a10cc9ac2..8b76fe957 100644
--- a/mandatory/1-syntax-errors.js
+++ b/mandatory/1-syntax-errors.js
@@ -1,18 +1,20 @@
 // 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";
+}
+let greet = introduceMe("Sonjide", 27);
+console.log(greet);
 
 function getTotal(a, b) {
-  total = a ++ b;
-
-  return "The total is total";
+  return "The total is " + (a + b);
 }
-
+let result = getTotal(14, 14);
+console.log(result);
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====
diff --git a/mandatory/2-logic-error.js b/mandatory/2-logic-error.js
index 9cca7603b..6883b1ef7 100644
--- a/mandatory/2-logic-error.js
+++ b/mandatory/2-logic-error.js
@@ -1,18 +1,30 @@
 // 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();
 }
+let myWord = trimWord("  codeyourfuture ");
+console.log(myWord.trim());
+myWord = trimWord(" codeyourfuture teaches coding   ");
+console.log(myWord.trim());
+
+
 
 function getStringLength(word) {
-  return "word".length();
+  return word.length;
+  
 }
 
+getStringLength("Turtles");
+getStringLength("A wild sentence appeared!");
+
 function multiply(a, b, c) {
-  a * b * c;
-  return;
+  return a * b * c;
+ 
 }
-
+let result = multiply(2, 3, 6);
+result = multiply(2, 3, 4);
+console.log(result);
 /* 
 ===================================================
 ======= TESTS - DO NOT MODIFY BELOW THIS LINE =====
diff --git a/mandatory/3-function-output.js b/mandatory/3-function-output.js
index 5a953ba60..808da627b 100644
--- a/mandatory/3-function-output.js
+++ b/mandatory/3-function-output.js
@@ -1,17 +1,36 @@
 // Add comments to explain what this function does. You're meant to use Google!
 function getRandomNumber() {
-  return Math.random() * 10;
+  return Math.random() * 10; // returns a random number from 0 to 9.
 }
 
 // Add comments to explain what this function does. You're meant to use Google!
 function combine2Words(word1, word2) {
-  return word1.concat(word2);
+  return word1.concat(word2);  // the concat() method joins two or more strings. It does not change the existing strings. It returns a new string. 
 }
 
+// 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 + secondWord + thirdWord;
+// }
+// let result = concatenate("code ", "your  ","future");
+// console.log(result);
+// result = concatenate("I ","like ","pizza");
+// console.log(result);
+// result = concatenate("I ","am ",13);
+// console.log(result);
+
 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 + " " + secondWord + " " + thirdWord;
 }
+let word = concatenate("code", "your", "future");
+console.log(word);
+word = concatenate("I", "like",  "pizza");
+console.log(word);
+word = concatenate("I",  "am",  13);
+console.log(word);
+
+
 
 /* 
 ===================================================
diff --git a/mandatory/4-tax.js b/mandatory/4-tax.js
index ba77c7ae2..2ee9cf50c 100644
--- a/mandatory/4-tax.js
+++ b/mandatory/4-tax.js
@@ -5,8 +5,16 @@
   Sales tax is 20% of the price of the product.
 */
 
-function calculateSalesTax() {}
+function calculateSalesTax(num) {
+  return num * 20 / 100 + num;
 
+}
+let sales = calculateSalesTax(15);
+console.log(sales);
+sales = calculateSalesTax(17.50);
+console.log(sales);
+sales = calculateSalesTax(34);
+console.log(sales);
 /*
   CURRENCY FORMATTING
   ===================
@@ -17,7 +25,16 @@ function calculateSalesTax() {}
   Remember that the prices must include the sales tax (hint: you already wrote a function for this!)
 */
 
-function addTaxAndFormatCurrency() {}
+function addTaxAndFormatCurrency(calculateSalesTax) {
+  let ProductTax = calculateSalesTax + (calculateSalesTax * 20) / 100;
+  let taxFormat = `£${ProductTax.toFixed(2)}`;
+  return taxFormat;
+}
+console.log(addTaxAndFormatCurrency(15));
+console.log(addTaxAndFormatCurrency(17.5));
+console.log(addTaxAndFormatCurrency(34));
+
+
 
 /* 
 ===================================================
diff --git a/package.json b/package.json
index 93e0861e3..6adc714df 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,9 @@
   "description": "Exercises for JS1 Week 1",
   "license": "CC-BY-SA-4.0",
   "scripts": {
-    "test": "jest"
+    "test": "jest", 
+    "extra-tests": "jest extra"
+     
   },
   "repository": {
     "type": "git",
@@ -15,6 +17,7 @@
   },
   "jest": {
     "setupFilesAfterEnv": ["jest-extended"],
+  
     "projects": [
       {
         "displayName": "mandatory",