diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
index 653d6f5a0..e37626f01 100644
--- a/Sprint-2/1-key-errors/0.js
+++ b/Sprint-2/1-key-errors/0.js
@@ -1,13 +1,21 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// The code will throw a SyntaxError
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
 
-function capitalise(str) {
+// Original code with error:
+/* function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
-}
+} */
 
 // =============> write your explanation here
+// The error occurs because because the variable 'str' is being redeclared inside the function.
+// The parameter 'str' is already defined, and trying to declare it again with 'let' causes a conflict.
+
 // =============> write your new code here
+function capitalise(str) {
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
+}
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
index f2d56151f..df1ad1fe9 100644
--- a/Sprint-2/1-key-errors/1.js
+++ b/Sprint-2/1-key-errors/1.js
@@ -2,9 +2,10 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// The error will occur because the variable 'decimalNumber' is being redeclared.
 
 // Try playing computer with the example to work out what is going on
-
+/*
 function convertToPercentage(decimalNumber) {
   const decimalNumber = 0.5;
   const percentage = `${decimalNumber * 100}%`;
@@ -13,8 +14,19 @@ function convertToPercentage(decimalNumber) {
 }
 
 console.log(decimalNumber);
+*/
 
 // =============> write your explanation here
+// The parameter decimalNumber is already declared as part of the function.
+// When we try to declare it again inside the function, it causes a syntax error because
+// we cannot redeclare a variable that is already declared in the same scope.
 
 // 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(0.5));
diff --git a/Sprint-2/1-key-errors/2.js b/Sprint-2/1-key-errors/2.js
index aad57f7cf..7d9c5e11e 100644
--- a/Sprint-2/1-key-errors/2.js
+++ b/Sprint-2/1-key-errors/2.js
@@ -1,20 +1,25 @@
-
 // Predict and explain first BEFORE you run any code...
+// It will throw a syntax error because 3 is not a valid.
 
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
-
+/*
 function square(3) {
     return num * num;
 }
-
+*/
 // =============> write the error message here
+// SyntaxError: Unexpected number
 
 // =============> explain this error message here
+// The error occurs because function parameters must be valid identifiers (i.e., variable names), not literal numbers.
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
+function square(num) {
+  return num * num;
+}
 
-
+console.log(square(3));
diff --git a/Sprint-2/2-mandatory-debug/0.js b/Sprint-2/2-mandatory-debug/0.js
index b27511b41..879d6828b 100644
--- a/Sprint-2/2-mandatory-debug/0.js
+++ b/Sprint-2/2-mandatory-debug/0.js
@@ -1,14 +1,22 @@
 // Predict and explain first...
 
 // =============> write your prediction here
-
+// I think it will return undefined.
+/*
 function multiply(a, b) {
   console.log(a * b);
 }
 
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
-
+*/
 // =============> write your explanation here
+// The function multiply does not have a return statement, so it returns undefined by default.
+// The string, it will show "The result of multiplying 10 and 32 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..99cc67035 100644
--- a/Sprint-2/2-mandatory-debug/1.js
+++ b/Sprint-2/2-mandatory-debug/1.js
@@ -1,13 +1,24 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// It will return undefined.
 
+/*
 function sum(a, b) {
   return;
   a + b;
 }
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+*/
 
 // =============> write your explanation here
+// The function sum returns nothing because the return statement is followed by a semicolon
+// and the expression `a + b` is not returned.
+
 // 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..0a1063639 100644
--- a/Sprint-2/2-mandatory-debug/2.js
+++ b/Sprint-2/2-mandatory-debug/2.js
@@ -2,7 +2,9 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// The output will be 3 in each expression.
 
+/*
 const num = 103;
 
 function getLastDigit() {
@@ -12,13 +14,31 @@ function getLastDigit() {
 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 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 function getLastDigit always returns the last digit of the variable `num`, which is 103.
+
 // 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
+
+// The function getLastDigit was not working properly because it was using a variable `num`
+// instead of the parameter passed to the function. By changing the function to accept a parameter `num`,
+// it now correctly returns the last digit of the number passed to it.
diff --git a/Sprint-2/3-mandatory-implement/1-bmi.js b/Sprint-2/3-mandatory-implement/1-bmi.js
index 17b1cbde1..40d8f094a 100644
--- a/Sprint-2/3-mandatory-implement/1-bmi.js
+++ b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -15,5 +15,6 @@
 // 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
+  // return the BMI of someone based off their weight and height
+  return Number((weight / (height * height)).toFixed(1));
+}
diff --git a/Sprint-2/3-mandatory-implement/2-cases.js b/Sprint-2/3-mandatory-implement/2-cases.js
index 5b0ef77ad..6dd1189c2 100644
--- a/Sprint-2/3-mandatory-implement/2-cases.js
+++ b/Sprint-2/3-mandatory-implement/2-cases.js
@@ -14,3 +14,9 @@
 // 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(input) {
+  return input.trim().toUpperCase().replace(/\s+/g, "_");
+}
+
+console.log(toUpperSnakeCase("manchester united")); // "MANCHESTER_UNITED"
diff --git a/Sprint-2/3-mandatory-implement/3-to-pounds.js b/Sprint-2/3-mandatory-implement/3-to-pounds.js
index 6265a1a70..32770a4d3 100644
--- a/Sprint-2/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-2/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,12 @@
 // 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(penceAmount) {
+  const padded = penceAmount.padStart(3, "0");
+  const pounds = padded.substring(0, padded.length - 2);
+  const pence = padded.substring(padded.length - 2);
+  return `£${pounds}.${pence}p`;
+}
+
+console.log(toPounds("399"));
diff --git a/Sprint-2/4-mandatory-interpret/time-format.js b/Sprint-2/4-mandatory-interpret/time-format.js
index 7c98eb0e8..3624abf17 100644
--- a/Sprint-2/4-mandatory-interpret/time-format.js
+++ b/Sprint-2/4-mandatory-interpret/time-format.js
@@ -18,17 +18,35 @@ function formatTimeDisplay(seconds) {
 
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
+// Answer: 3 times
+// pad(totalHours)
+// pad(remainingMinutes)
+// pad(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
+// pad(num) = pad(0) = 0
 
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+// pad(num) = pad(0) = "00"
 
 // 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
+// Answer: pad(num) = pad(1) = 1
+// Explanation below:
+// Last call: pad(remainingSeconds)
+// remainingSeconds = 1
+// pad(1) → num = 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
+// Answer: pad(num) = pad(1) = "01"
+// Explanation below:
+// Last call: pad(remainingSeconds)
+// remainingSeconds = 1
+// toString() → "1"
+// "1".padStart(2, "0") → "01"
+// pad(1) → "01"