diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
index 60c9ace69..6d9e74e26 100644
--- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js
+++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
@@ -25,3 +25,4 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+
diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
index 653d6f5a0..b95a41047 100644
--- a/Sprint-2/1-key-errors/0.js
+++ b/Sprint-2/1-key-errors/0.js
@@ -1,13 +1,24 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// The code will throw an error because the variable 'str' is being redeclared with 'let' inside the function,
+// which is not allowed since 'str' is already defined as a parameter of the function.
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
+// function capitalise(str) {
+//   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+//   return str;
+// }
+
+// =============> write your explanation here
+// The error occurs because the variable 'str' is being declared again with 'let' inside the function,
+// which conflicts with the parameter 'str' that is already defined. In JavaScript, you cannot redeclare a variable with 'let' in the same scope.
+// =============> write your new code here
 function capitalise(str) {
-  let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+console.log(capitalise("hello"));  // Output: "Hello"
+
 
-// =============> write your explanation here
-// =============> write your new code here
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
index f2d56151f..2a8efff38 100644
--- a/Sprint-2/1-key-errors/1.js
+++ b/Sprint-2/1-key-errors/1.js
@@ -2,19 +2,30 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// The code will throw an error because the variable 'decimalNumber' is being redeclared with 'const' inside the function,
+// which is not allowed since 'decimalNumber' is already defined as a parameter of the function
 
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
-
-  return percentage;
-}
+// function convertToPercentage(decimalNumber) {
+//   const decimalNumber = 0.5;
+//   const percentage = `${decimalNumber * 100}%`;
 
-console.log(decimalNumber);
+//   return percentage;
+// }
+// console.log(decimalNumber);
 
 // =============> write your explanation here
+// The error occurs because the variable 'decimalNumber' is being declared again with 'const' inside the function,
+// which conflicts with the parameter 'decimalNumber' that is already defined. In JavaScript,
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+function convertToPercentage(decimalNumber) {
+ // decimalNumber = 0.5; // Remove 'const' to avoid redeclaration
+  const percentage = `${decimalNumber * 100}%`;
+
+  return percentage;
+}
+console.log(convertToPercentage(0.5)); // Output: "50%"
+console.log(convertToPercentage(0.1)); // Output: "10%"
\ 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..37bc839c6 100644
--- a/Sprint-2/1-key-errors/2.js
+++ b/Sprint-2/1-key-errors/2.js
@@ -4,17 +4,26 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// The code will throw an error because the function is trying to use a number literal (3) as a parameter name,
+// which is not allowed in JavaScript. Function parameters must be valid identifiers, and a number
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
 
 // =============> write the error message here
+// SyntaxError: Unexpected number in parameter list
 
 // =============> explain this error message here
+// The error message indicates that there is a syntax error because the function parameter cannot be a number.
+// Function parameters must be valid identifiers, and using a number as a parameter name is not allowed
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
+function square(num) {
+    return num * num;
+}
+console.log(square(3)); // Output: 9
 
 
diff --git a/Sprint-2/2-mandatory-debug/0.js b/Sprint-2/2-mandatory-debug/0.js
index b27511b41..abd468f37 100644
--- a/Sprint-2/2-mandatory-debug/0.js
+++ b/Sprint-2/2-mandatory-debug/0.js
@@ -1,14 +1,25 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// This code will not produce the expected string output. Instead, it will:
+// Log the result of the multiplication directly (320)
+// Then print:The result of multiplying 10 and 32 is undefined
 
-function multiply(a, b) {
-  console.log(a * b);
-}
+// function multiply(a, b) {
+//   console.log(a * b);
+// }
 
-console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
+// console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+// multiply(10, 32) runs inside the template literal.
+// Inside the multiply function, console.log(a * b) prints 320 to the console.
+// However, the multiply function does not return a value → so it returns undefined by default.
 
 // Finally, correct the code to fix the problem
+//You should return the result from the function instead of logging it directly:
+function multiply(a, b) {
+  return a * b;
+}
+console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 //  =============> write your new code here
diff --git a/Sprint-2/2-mandatory-debug/1.js b/Sprint-2/2-mandatory-debug/1.js
index 37cedfbcf..59fc2e78d 100644
--- a/Sprint-2/2-mandatory-debug/1.js
+++ b/Sprint-2/2-mandatory-debug/1.js
@@ -1,13 +1,23 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// This code will output:
+// The sum of 10 and 32 is undefined
+// because the sum function does not return a value.
+// function sum(a, b) {
+//   return;
+//   a + b;
+// }
 
-function sum(a, b) {
-  return;
-  a + b;
-}
-
-console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+// console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+// The sum function does not return a value because the return statement is immediately followed by a semicolon.
+// This means the function exits before it can execute the a + b expression.
+
 // Finally, correct the code to fix the problem
-//  =============> write your new code here
+// =============> write your new code here
+function sum(a, b) {
+  return a + b; // Corrected to return the sum of a and b
+}
+console.log(`The sum of 10 and 32 is ${sum(10, 32)}`); // Output: The sum of 10 and 32 is 42
+
diff --git a/Sprint-2/2-mandatory-debug/2.js b/Sprint-2/2-mandatory-debug/2.js
index 57d3f5dc3..113c26f53 100644
--- a/Sprint-2/2-mandatory-debug/2.js
+++ b/Sprint-2/2-mandatory-debug/2.js
@@ -2,23 +2,54 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// The last digit of 42 is undefined
+// The last digit of 105 is undefined
+// The last digit of 806 is undefined
 
-const num = 103;
 
-function getLastDigit() {
-  return num.toString().slice(-1);
-}
+// const num = 103;
 
-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)}`);
+// function getLastDigit() {
+//   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)}`);
 
 // Now run the code and compare the output to your prediction
 // =============> write the output here
+// The last digit of 42 is undefined
+// The last digit of 105 is undefined
+// The last digit of 806 is undefined
 // Explain why the output is the way it is
 // =============> write your explanation here
+// The output is undefined because the getLastDigit function does not accept any parameters.
+// It always uses the global variable num, which is set to 103.
+// The function getLastDigit should take a number as an argument and return its last digit.
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+
+
 // This program should tell the user the last digit of each number.
+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)}`);
+
 // Explain why getLastDigit is not working properly - correct the problem
+// =============> write your explanation here
+// The getLastDigit function is not working properly because it does not accept any parameters.
+// It should take a number as an argument and return its last digit.
+// The corrected function now accepts a number as an argument and returns its last digit correctly.
+// The function now works as intended, returning the last digit of each number passed to it.
+// The output will now be:
+// The last digit of 42 is 2
+// The last digit of 105 is 5
+// The last digit of 806 is 6
+
+
diff --git a/Sprint-2/3-mandatory-implement/1-bmi.js b/Sprint-2/3-mandatory-implement/1-bmi.js
index 17b1cbde1..c06f31603 100644
--- a/Sprint-2/3-mandatory-implement/1-bmi.js
+++ b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -16,4 +16,18 @@
 
 function calculateBMI(weight, height) {
     // return the BMI of someone based off their weight and height
-}
\ No newline at end of file
+    if (height <= 0) {
+        throw new Error("Height must be greater than zero.");
+    }
+    if (weight <= 0) {
+        throw new Error("Weight must be greater than zero.");
+    }
+    const bmi = weight / (height * height);
+    return parseFloat(bmi.toFixed(1)); // Return BMI to 1 decimal place
+}
+// Example usage:
+ const weight = 70; // in kg
+ const height = 1.73; // in metres
+ const bmi = calculateBMI(weight, height);
+ console.log(`Your BMI is: ${bmi}`); // Output: Your BMI is: 23.4
+
diff --git a/Sprint-2/3-mandatory-implement/2-cases.js b/Sprint-2/3-mandatory-implement/2-cases.js
index 5b0ef77ad..1cebc7296 100644
--- a/Sprint-2/3-mandatory-implement/2-cases.js
+++ b/Sprint-2/3-mandatory-implement/2-cases.js
@@ -8,9 +8,26 @@
 // Given a string input like "hello there"
 // When we call this function with the input string
 // it returns the string in UPPER_SNAKE_CASE, so "HELLO_THERE"
+function toUpperSnakeCase(input) {
+    // Check if input is a string
+    if (typeof input !== 'string') {
+        throw new Error("Input must be a string.");
+    }
+    // Convert the string to uppercase and replace spaces with underscores
+    return input.toUpperCase().replace(/ /g, '_');
+}
+// Example usage:
+const inputString = "hello there";
+const upperSnakeCaseString = toUpperSnakeCase(inputString);
+console.log(upperSnakeCaseString); // Output: "HELLO_THERE"
 
 // Another example: "lord of the rings" should be "LORD_OF_THE_RINGS"
 
+const inputString1 = "LORD_OF_THE_RINGS";
+const upperSnakeCaseString1 = toUpperSnakeCase(inputString1);
+console.log(upperSnakeCaseString1); // Output: "LORD_OF_THE_RINGS"
+
+
 // 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
diff --git a/Sprint-2/3-mandatory-implement/3-to-pounds.js b/Sprint-2/3-mandatory-implement/3-to-pounds.js
index 6265a1a70..4480e6ff1 100644
--- a/Sprint-2/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-2/3-mandatory-implement/3-to-pounds.js
@@ -2,5 +2,24 @@
 
 // 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) {
+  // Remove the trailing "p"
+  const penceStringWithoutTrailingP = penceString.slice(0, -1);
+
+  // Pad the string so it's at least 3 digits
+  const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+
+  // Extract pounds and pence
+  const pounds = paddedPenceNumberString.slice(0, -2);
+  const pence = paddedPenceNumberString.slice(-2).padEnd(2, "0");
+
+  return `£${pounds}.${pence}`;
+}
+
+// Test cases
+console.log(toPounds("399p")); // £3.99
+console.log(toPounds("99p"));  // £0.99
+console.log(toPounds("9p"));   // £0.09
+console.log(toPounds("1234p")); // £12.34
\ No newline at end of file
diff --git a/Sprint-2/4-mandatory-interpret/time-format.js b/Sprint-2/4-mandatory-interpret/time-format.js
index 7c98eb0e8..30b6d0e2e 100644
--- a/Sprint-2/4-mandatory-interpret/time-format.js
+++ b/Sprint-2/4-mandatory-interpret/time-format.js
@@ -1,6 +1,7 @@
 function pad(num) {
-  return num.toString().padStart(2, "0");
-}
+   console.log(num); 
+  return num.toString().padStart(2, "0"); 
+} 
 
 function formatTimeDisplay(seconds) {
   const remainingSeconds = seconds % 60;
@@ -9,7 +10,7 @@ function formatTimeDisplay(seconds) {
   const totalHours = (totalMinutes - remainingMinutes) / 60;
 
   return `${pad(totalHours)}:${pad(remainingMinutes)}:${pad(remainingSeconds)}`;
-}
+} 
 
 // You will need to play computer with this example - use the Python Visualiser https://pythontutor.com/visualize.html#mode=edit
 // to help you answer these questions
@@ -18,17 +19,26 @@ function formatTimeDisplay(seconds) {
 
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
+// The function formatTimeDisplay will call pad three times: once for totalHours, once for remainingMinutes, and once for remainingSeconds.
 
 // 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
+// The value assigned to num when pad is called for the first time is 0. 
+// The first call to pad is for totalHours, which is 1.
 
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+// The return value of pad when called for the first time is "01". This is because pad converts the number 1 to a string and pads it with a leading zero to ensure it has at least 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 value assigned to num when pad is called for the last time is 1. This is because remainingSeconds is calculated as 61 % 60, which equals 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 return value assigned to num when pad is called for the last time is "01".
+//  This is because pad converts the number 1 to a string and pads it with a leading zero to ensure it has at least two digits.
+// The final output of formatTimeDisplay(61) will be "00:01:01", where each component is padded to two digits.
+console.log(formatTimeDisplay(61)); // Output: "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..10cee0e39 100644
--- a/Sprint-2/5-stretch-extend/format-time.js
+++ b/Sprint-2/5-stretch-extend/format-time.js
@@ -2,24 +2,61 @@
 // Make sure to do the prep before you do the coursework
 // 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) {
+//   const hours = Number(time.slice(0, 2));
+//   if (hours > 12) {
+//     return `${hours - 12}:00 pm`;
+//   }
+//   return `${time} am`;
+// }
+
+// const currentOutput = formatAs12HourClock("08:00");
+// const targetOutput = "08:00 am";
+// console.assert(
+//   currentOutput === targetOutput,
+//   `current output: ${currentOutput}, target output: ${targetOutput}`
+// );
+
+// const currentOutput2 = formatAs12HourClock("23:00");
+// const targetOutput2 = "11:00 pm";
+// console.assert(
+//   currentOutput2 === targetOutput2,
+//   `current output: ${currentOutput2}, target output: ${targetOutput2}`
+// );
+// It only handles ":00" times — doesn't process the minutes properly.
+// It returns "08:00 am" even though the 08:00 input results in "08:00 am" due to hardcoding the entire string.
+// It does not handle: /Midnight (00:00) /Noon (12:00) /Times with non-zero minutes (e.g., 13:45)
+// It always appends " am" even if time is 12:00 noon or later.
 function formatAs12HourClock(time) {
-  const hours = Number(time.slice(0, 2));
-  if (hours > 12) {
-    return `${hours - 12}:00 pm`;
-  }
-  return `${time} am`;
+  const [hourStr, minuteStr] = time.split(":");
+  let hours = Number(hourStr);
+  const suffix = hours >= 12 ? "pm" : "am";
+
+  hours = hours % 12;
+  if (hours === 0) hours = 12;
+
+  const formattedHour = String(hours).padStart(2, "0");
+
+  return `${formattedHour}:${minuteStr} ${suffix}`;
 }
 
-const currentOutput = formatAs12HourClock("08:00");
-const targetOutput = "08:00 am";
-console.assert(
-  currentOutput === targetOutput,
-  `current output: ${currentOutput}, target output: ${targetOutput}`
-);
-
-const currentOutput2 = formatAs12HourClock("23:00");
-const targetOutput2 = "11:00 pm";
-console.assert(
-  currentOutput2 === targetOutput2,
-  `current output: ${currentOutput2}, target output: ${targetOutput2}`
-);
+// Test cases
+const testCases = [
+  { input: "08:00", expected: "08:00 am" },
+  { input: "23:00", expected: "11:00 pm" },
+  { input: "12:00", expected: "12:00 pm" },
+  { input: "00:00", expected: "12:00 am" },
+  { input: "13:45", expected: "01:45 pm" },
+  { input: "11:30", expected: "11:30 am" },
+  { input: "15:15", expected: "03:15 pm" },
+];
+
+testCases.forEach(({ input, expected }) => {
+  const output = formatAs12HourClock(input);
+  console.assert(output === expected, `Test failed for ${input}: got ${output}, expected ${expected}`);
+});
+
+console.log("✅ All tests completed");
+// This function now correctly formats times in 12-hour clock format, handling edge cases like midnight and noon, and works with any minute value.
+// It also passes all the test cases provided, ensuring that it behaves as expected for a variety of inputs.
+