diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
index 653d6f5a0..f820cd787 100644
--- a/Sprint-2/1-key-errors/0.js
+++ b/Sprint-2/1-key-errors/0.js
@@ -1,5 +1,6 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// The variable str is being declared twice within the same scope, which will cause a syntax error.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -8,6 +9,17 @@ function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+const result = capitalise('hello');
+console.log(result);
+// SyntaxError: Identifier 'str' has already been declared
 
 // =============> write your explanation here
+// // The first declaration is in the function parameter and the second one is inside the function body.
+// In JavaScript, you cannot declare the same variable name in the same scope using let or const.
+// To fix this, we can either rename the inner variable or assign the capitalised value to the parameter itself without redeclaring it.
+
 // =============> write your new code here
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+} 
\ No newline at end of file
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
index f2d56151f..155b52d2e 100644
--- a/Sprint-2/1-key-errors/1.js
+++ b/Sprint-2/1-key-errors/1.js
@@ -1,20 +1,29 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// constant decimalNumber is being declared twice within the same scope, which will cause a syntax error.
 
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
+//function convertToPercentage(decimalNumber) {
+  //const decimalNumber = 0.5;
+  //const percentage = `${decimalNumber * 100}%`;
 
-  return percentage;
-}
+  //return percentage;
+//}
 
-console.log(decimalNumber);
+//console.log(decimalNumber);
 
 // =============> write your explanation here
+// SyntaxError: Identifier 'decimalNumber' has already been declared
+// decimalNumber is declared as a parameter of the function and then again inside the function using const.
+// In JavaScript, you cannot declare the same variable name in the same scope using let or const.
+// Function input is ignored if a variable with the same name is declared inside the function body.
+// const decimalNumber = 0.5 will always output 50% regardless of the input value.
 
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+  return percentage;
+}
+console.log(convertToPercentage(0.75)); // Example call to test the function
\ No newline at end of file
diff --git a/Sprint-2/1-key-errors/2.js b/Sprint-2/1-key-errors/2.js
index aad57f7cf..e96750a29 100644
--- a/Sprint-2/1-key-errors/2.js
+++ b/Sprint-2/1-key-errors/2.js
@@ -3,18 +3,26 @@
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// The function does not define the parameter correctly
+// Instead, the input has been inserted where the parameter name should be 
+// Then num is being used in the function body but it is not defined anywhere
 
-function square(3) {
-    return num * num;
-}
-
-// =============> write the error message here
+// function square(3) {
+   // return num * num;
+// }
 
-// =============> explain this error message here
+// SyntaxError: Unexpected number
+// The number 3 is used directly in the function parameter 
+// The function parameter should be num to accept any number as input
+// Then the function body can use num to square the input value
+//Defining a function should describe the parameters it expects, not specific values
 
 // Finally, correct the code to fix the problem
-
-// =============> write your new code here
+function square(num) {
+    return num * num;
+}
+console.log(square(5)); 
+console.log(square(10));
+console.log(square(-3));
 
 
diff --git a/Sprint-2/2-mandatory-debug/0.js b/Sprint-2/2-mandatory-debug/0.js
index b27511b41..f60739987 100644
--- a/Sprint-2/2-mandatory-debug/0.js
+++ b/Sprint-2/2-mandatory-debug/0.js
@@ -1,6 +1,7 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// console.log is being used inside the multiply function, which does not return any value.
+// This will result in undefined being printed in the template literal.
 
 function multiply(a, b) {
   console.log(a * b);
@@ -8,7 +9,15 @@ function multiply(a, b) {
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
-// =============> write your explanation here
+// Output in the terminal was: "320
+// The result of multiplying 10 and 32 is undefined"
+// Console.log within the function prints the product of the calculation, but the function does not return the value to the global scope.
+// Therefore within the template literal, the meaning of the multiply function call is undefined
 
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+
+function multiply(a, b) {
+  return a * b;
+}
+
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
diff --git a/Sprint-2/2-mandatory-debug/1.js b/Sprint-2/2-mandatory-debug/1.js
index 37cedfbcf..001d527b0 100644
--- a/Sprint-2/2-mandatory-debug/1.js
+++ b/Sprint-2/2-mandatory-debug/1.js
@@ -1,5 +1,6 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  a + b should be written on the same line as return statement
+// This function will not return anything because of the semicolon, so when the function is call on line 10 it will be undefined.
 
 function sum(a, b) {
   return;
@@ -8,6 +9,11 @@ function sum(a, b) {
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
-// =============> write your explanation here
+// Terminal output "The sum of 10 and 32 is undefined"
+// Console.log is calling a function that was not defined because the function body has an incorrect return statement.
+
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+function sum(a, b) {
+return a + b;
+}
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
diff --git a/Sprint-2/2-mandatory-debug/2.js b/Sprint-2/2-mandatory-debug/2.js
index 57d3f5dc3..6ed853c62 100644
--- a/Sprint-2/2-mandatory-debug/2.js
+++ b/Sprint-2/2-mandatory-debug/2.js
@@ -1,7 +1,8 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// This function will always return the last digit of the number 103.
+// This is because the variable num is hardcoded to 103 within the function scope.
 
 const num = 103;
 
@@ -14,11 +15,21 @@ console.log(`The last digit of 105 is ${getLastDigit(105)}`);
 console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
 // Now run the code and compare the output to your prediction
-// =============> write the output here
+// The last digit of 42 is 3
+// The last digit of 105 is 3
+// The last digit of 806 is 3
+
 // Explain why the output is the way it is
-// =============> write your explanation here
+// The number 103 is assigned as a constant variable so the function will always use num as 103
+// So when the function is called with different arguments, it still returns the last digit of 103 which is 3
+
 // Finally, correct the code to fix the problem
-// =============> write your new code here
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+console.log(`The last digit of 42 is ${getLastDigit(42)}`);
+console.log(`The last digit of 105 is ${getLastDigit(105)}`);
+console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
 // This program should tell the user the last digit of each number.
 // Explain why getLastDigit is not working properly - correct the problem
diff --git a/Sprint-2/3-mandatory-implement/1-bmi.js b/Sprint-2/3-mandatory-implement/1-bmi.js
index 17b1cbde1..5ebbab192 100644
--- a/Sprint-2/3-mandatory-implement/1-bmi.js
+++ b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -1,19 +1,24 @@
 // Below are the steps for how BMI is calculated
-
 // The BMI calculation divides an adult's weight in kilograms (kg) by their height in metres (m) squared.
-
 // For example, if you weigh 70kg (around 11 stone) and are 1.73m (around 5 feet 8 inches) tall, you work out your BMI by:
-
 // squaring your height: 1.73 x 1.73 = 2.99
 // dividing 70 by 2.99 = 23.41
 // Your result will be displayed to 1 decimal place, for example 23.4.
-
 // You will need to implement a function that calculates the BMI of someone based off their weight and height
-
 // Given someone's weight in kg and height in metres
 // Then when we call this function with the weight and height
 // It should return their Body Mass Index to 1 decimal place
 
 function calculateBMI(weight, height) {
-    // return the BMI of someone based off their weight and height
-}
\ No newline at end of file
+    let bmi = (weight / (height * height));
+    return Number(bmi.toFixed(1));
+}
+console.log(calculateBMI(70, 1.73));
+console.log(calculateBMI(95, 1.82));
+console.log(calculateBMI(52, 1.6));
+console.log(calculateBMI(110, 1.75));
+console.log(calculateBMI(65, 1.9));
+
+console.assert(typeof calculateBMI(60, 1.65) === 'number', 'Should return a number');
+console.assert(calculateBMI(60, 1.65) === 22.0, 'Should correctly calculate BMI');
+console.log('All tests passed!');
\ No newline at end of file
diff --git a/Sprint-2/3-mandatory-implement/2-cases.js b/Sprint-2/3-mandatory-implement/2-cases.js
index 5b0ef77ad..5408c5708 100644
--- a/Sprint-2/3-mandatory-implement/2-cases.js
+++ b/Sprint-2/3-mandatory-implement/2-cases.js
@@ -14,3 +14,11 @@
 // You will need to come up with an appropriate name for the function
 // Use the MDN string documentation to help you find a solution
 // This might help https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toUpperCase
+
+function toUpperSnakeCase(string) {
+    return string.toUpperCase().replace(/ /g, "_");
+}
+console.log(toUpperSnakeCase("hello there"));   
+console.log(toUpperSnakeCase("lord of the rings"));  
+console.log(toUpperSnakeCase("javascript 4eva"));  
+console.log(toUpperSnakeCase("unit testing is important!!"));
\ No newline at end of file
diff --git a/Sprint-2/3-mandatory-implement/3-to-pounds.js b/Sprint-2/3-mandatory-implement/3-to-pounds.js
index 6265a1a70..a631616a2 100644
--- a/Sprint-2/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-2/3-mandatory-implement/3-to-pounds.js
@@ -1,6 +1,37 @@
 // In Sprint-1, there is a program written in interpret/to-pounds.js
-
 // You will need to take this code and turn it into a reusable block of code.
 // You will need to declare a function called toPounds with an appropriately named parameter.
-
 // You should call this function a number of times to check it works for different inputs
+
+function toPounds(penceString) {
+  penceString = String(penceString); // ensures input is treated as a string even if number is inputted
+  // const penceStringWithoutTrailingP = penceString.substring(
+  let penceStringWithoutTrailingP = penceString;
+  if (penceString.endsWith("p")) {
+    penceStringWithoutTrailingP = penceString.substring(
+      0,
+      penceString.length - 1
+    );
+  } // This prevents the last characters from being sliced off if there is no p.
+
+  const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+  const pounds = paddedPenceNumberString.substring(
+    0,
+    paddedPenceNumberString.length - 2
+  );
+
+  const pence = paddedPenceNumberString
+    .substring(paddedPenceNumberString.length - 2)
+    .padEnd(2, "0");
+
+  return `£${pounds}.${pence}`;
+}
+console.log(toPounds("481p"));
+console.log(toPounds("50p"));
+console.log(toPounds("5p"));
+console.log(toPounds("0p"));
+console.log(toPounds("12345p"));
+console.log(toPounds("9")); // edge case: missing 'p' at the end, returns 0 rather than error because last character is sliced off
+// Can be fixed by changing line 8
+console.log(toPounds("abc")); // Works but returns nonsense value
+console.log(toPounds(123)); // Works with number input because of line 7 converting to string
diff --git a/Sprint-2/4-mandatory-interpret/time-format.js b/Sprint-2/4-mandatory-interpret/time-format.js
index 7c98eb0e8..8afc4a223 100644
--- a/Sprint-2/4-mandatory-interpret/time-format.js
+++ b/Sprint-2/4-mandatory-interpret/time-format.js
@@ -2,7 +2,7 @@ function pad(num) {
   return num.toString().padStart(2, "0");
 }
 
-function formatTimeDisplay(seconds) {
+function formatTimeDisplay(num) {
   const remainingSeconds = seconds % 60;
   const totalMinutes = (seconds - remainingSeconds) / 60;
   const remainingMinutes = totalMinutes % 60;
@@ -17,18 +17,23 @@ function formatTimeDisplay(seconds) {
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// 3 times: the return statement contains 3 pad calls within the formatTimeDisplay function.
 
 // Call formatTimeDisplay with an input of 61, now answer the following:
 
 // b) What is the value assigned to num when pad is called for the first time?
-// =============> write your answer here
+// num = 0 as when the input is 61 seconds, remainingSeconds = 1, totalMinutes = 1, remainingMinutes = 1, totalHours = 0. 
+// totalHours = (totalMinutes - remainingMinutes) / 60 = (1 - 1) / 60 = 0 / 60 = 0 (dividing once into minutes and once into hours).
 
-// c) What is the return value of pad is called for the first time?
-// =============> write your answer here
+// c) What is the return value of pad when called for the first time?
+// "00" as num is 0, and padStart(2, "0") adds a leading zero to make it two digits.
 
 // d) What is the value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// The last time pad is called, num is assigned the value of remainingSeconds, which is 1.
+// Go to line const remainingSeconds = seconds % 60; and use input of seconds = 61 to calculate remainder of 61/60 = 1
 
 // e) What is the return value assigned to num when pad is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// The last time pad is called, it uses remainingSeconds which is 1
+// The call is pad(1) which converts to a string and adds a leading 0 if there's less than 2 characters
+// So, the return value is "01". 
+// The final formatted time string for an input of 61 seconds is "00:01:01". 
diff --git a/Sprint-2/5-stretch-extend/format-time.js b/Sprint-2/5-stretch-extend/format-time.js
index 32a32e66b..04c219987 100644
--- a/Sprint-2/5-stretch-extend/format-time.js
+++ b/Sprint-2/5-stretch-extend/format-time.js
@@ -3,10 +3,18 @@
 // Your task is to write tests for as many different groups of input data or edge cases as you can, and fix any bugs you find.
 
 function formatAs12HourClock(time) {
+  if (!/^\d{2}:\d{2}$/.test(time)) { //If input does not match HH:MM format, returns string "Invalid time format"
+  return "Invalid time format";
+}
+
   const hours = Number(time.slice(0, 2));
-  if (hours > 12) {
-    return `${hours - 12}:00 pm`;
-  }
+  const minutes = time.slice(-2);
+
+ if (hours === 0) return `12:${minutes} am`;
+  if (hours === 12) return `12:${minutes} pm`;
+    if (hours === 24) return `12:${minutes} am`;
+   if (hours > 12) return `${hours - 12}:${minutes} pm`;
+
   return `${time} am`;
 }
 
@@ -23,3 +31,10 @@ console.assert(
   currentOutput2 === targetOutput2,
   `current output: ${currentOutput2}, target output: ${targetOutput2}`
 );
+
+console.log(formatAs12HourClock("12:00")); // 
+console.log(formatAs12HourClock("00:00")); //
+console.log(formatAs12HourClock("15:30")); //
+console.log(formatAs12HourClock("11:45")); //
+console.log(formatAs12HourClock("24:00")); //
+console.log(formatAs12HourClock("ab:cd")); //