diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
index 653d6f5a0..227bd3158 100644
--- a/Sprint-2/1-key-errors/0.js
+++ b/Sprint-2/1-key-errors/0.js
@@ -4,10 +4,15 @@
 // 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;
-}
+// function capitalise(str) {
+//   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+//   return str;
+// }
 
 // =============> write your explanation here
 // =============> write your new code here
+function capitalise(str) {
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
+}
+
+console.log(capitalise("hello"));
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
index f2d56151f..d699325d1 100644
--- a/Sprint-2/1-key-errors/1.js
+++ b/Sprint-2/1-key-errors/1.js
@@ -5,16 +5,22 @@
 
 // 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
 
 // 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));
\ 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..f545fc449 100644
--- a/Sprint-2/1-key-errors/2.js
+++ b/Sprint-2/1-key-errors/2.js
@@ -1,20 +1,29 @@
-
 // Predict and explain first BEFORE you run any code...
 
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// SyntaxError: Unexpected number
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
 
 // =============> write the error message here
+// SyntaxError: Unexpected number
 
 // =============> explain this error message here
+// The function parameter is written as 3, which is a number literal.
+// Function parameters must be variable names (identifiers).
+// JavaScript does not allow numbers as parameter names,
+// so it throws a SyntaxError before running the program.
 
 // 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-2/1-key-errors/answers.md b/Sprint-2/1-key-errors/answers.md
new file mode 100644
index 000000000..0cadbfafa
--- /dev/null
+++ b/Sprint-2/1-key-errors/answers.md
@@ -0,0 +1,101 @@
+# Sprint 2 - 1 Key Errors (Answers)
+
+## 0.js
+- Predicted error:
+- Actual error:
+- Why it happens:
+- Minimal fix:
+- Docs:
+
+## 1.js
+- Predicted error:
+- Actual error:
+- Why it happens:
+- Minimal fix:
+- Docs:
+
+## 2.js
+- Predicted error:
+- Actual error:
+- Why it happens:
+- Minimal fix:
+
+
+
+## 0.js
+
+- Predicted error: SyntaxError (variable redeclaration)
+
+- Actual error: SyntaxError: Identifier 'str' has already been declared
+
+- Why it happens:  
+  The function parameter `str` is already declared. Inside the function, `let str = ...` attempts to redeclare the same variable in the same scope. JavaScript does not allow redeclaration of variables using `let`.
+
+- Minimal fix:  
+  Remove the `let` and return the new string directly:
+
+  ```js
+  function capitalise(str) {
+    return `${str[0].toUpperCase()}${str.slice(1)}`;
+  }
+
+  - Docs:  
+  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let
+
+
+
+  ## 1.js
+- Predicted error: SyntaxError (variable redeclaration)
+
+- Actual error: SyntaxError: Identifier 'decimalNumber' has already been declared
+
+- Why it happens:  
+  The function parameter `decimalNumber` is already declared. Inside the function, `const decimalNumber = 0.5;` attempts to redeclare the same variable in the same scope. JavaScript does not allow redeclaration using `const`.
+
+  There is also a second issue:  
+  `console.log(decimalNumber);` is outside the function, and `decimalNumber` is not defined in the global scope. This would cause a ReferenceError.
+
+- Concepts tested:  
+  Variable scope, function parameters, redeclaration rules, global vs local variables.
+
+  function convertToPercentage(decimalNumber) {
+  const percentage = `${decimalNumber * 100}%`;
+  return percentage;
+}
+
+console.log(convertToPercentage(0.5));
+
+
+
+
+## 2.js
+
+- Predicted error: SyntaxError (invalid function parameter)
+
+- Actual error: SyntaxError: Unexpected number
+
+- Why it happens:  
+  The function is declared as `function square(3)`.  
+  Function parameters must be variable names (identifiers), not literal values.  
+  The number `3` is not a valid parameter name, so JavaScript throws a syntax error.
+
+- Concept tested:  
+  Function declaration syntax and valid parameter identifiers.
+
+- Minimal fix:
+
+```js
+function square(number) {
+  return number * number;
+}
+
+console.log(square(3));
+
+
+
+
+
+
+
+
+
diff --git a/Sprint-2/2-mandatory-debug/0.js b/Sprint-2/2-mandatory-debug/0.js
index b27511b41..c6086cab8 100644
--- a/Sprint-2/2-mandatory-debug/0.js
+++ b/Sprint-2/2-mandatory-debug/0.js
@@ -1,14 +1,29 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// The function will print 320 from inside multiply,
+// but the final console.log will show "undefined"
+// because multiply does not return a value.
 
-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
+// The function multiply only logs the result using console.log,
+// but it does not return the value.
+// Since it does not return anything, JavaScript returns undefined by default.
+// Therefore, the template string inserts 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..b98071272 100644
--- a/Sprint-2/2-mandatory-debug/1.js
+++ b/Sprint-2/2-mandatory-debug/1.js
@@ -1,13 +1,27 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// The function will return undefined because the return statement
+// is followed by a line break. JavaScript inserts a semicolon automatically,
+// so the function exits before a + b is executed.
 
-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 return statement is on its own line.
+// JavaScript automatically inserts a semicolon after return.
+// This means the function returns undefined immediately,
+// and the expression a + b is never executed.
+
 // 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)}`);
\ No newline at end of file
diff --git a/Sprint-2/2-mandatory-debug/2.js b/Sprint-2/2-mandatory-debug/2.js
index 57d3f5dc3..f37ddbb8a 100644
--- a/Sprint-2/2-mandatory-debug/2.js
+++ b/Sprint-2/2-mandatory-debug/2.js
@@ -2,23 +2,38 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// The function will always return 3 because it uses the global variable num (103).
+// So all outputs will show 3 regardless of the input.
 
-const num = 103;
+// const num = 103;
 
-function getLastDigit() {
-  return num.toString().slice(-1);
-}
+// 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)}`);
+// 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 does not take a parameter, so it ignores the values passed in.
+// It always uses the global variable num (which is 103).
+// Therefore, it always returns the last digit of 103, which is 3.
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
-// This program should tell the user the last digit of each number.
-// Explain why getLastDigit is not working properly - correct the problem
+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)}`);
\ No newline at end of file
diff --git a/Sprint-2/3-mandatory-implement/1-bmi.js b/Sprint-2/3-mandatory-implement/1-bmi.js
index 17b1cbde1..944479920 100644
--- a/Sprint-2/3-mandatory-implement/1-bmi.js
+++ b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -14,6 +14,20 @@
 // 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
+// }
+
+
 function calculateBMI(weight, height) {
-    // return the BMI of someone based off their weight and height
-}
\ No newline at end of file
+  const bmi = weight / (height * height);
+  return bmi.toFixed(1);
+}
+
+// Test cases
+console.log(calculateBMI(70, 1.73)); // Output: 23.4
+console.log(calculateBMI(80, 1.8));  // Output: 24.7
+
+
+
+
diff --git a/Sprint-2/3-mandatory-implement/2-cases.js b/Sprint-2/3-mandatory-implement/2-cases.js
index 5b0ef77ad..142ea3fcc 100644
--- a/Sprint-2/3-mandatory-implement/2-cases.js
+++ b/Sprint-2/3-mandatory-implement/2-cases.js
@@ -14,3 +14,13 @@
 // 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(str) {
+  return str.replaceAll(" ", "_").toUpperCase();
+}
+
+// Test cases
+console.log(toUpperSnakeCase("hello there")); // HELLO_THERE
+console.log(toUpperSnakeCase("lord of the rings")); // LORD_OF_THE_RINGS
+
diff --git a/Sprint-2/3-mandatory-implement/3-to-pounds.js b/Sprint-2/3-mandatory-implement/3-to-pounds.js
index 6265a1a70..ee531dd6e 100644
--- a/Sprint-2/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-2/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,31 @@
 // 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) {
+  const penceStringWithoutTrailingP = penceString.substring(
+    0,
+    penceString.length - 1
+  );
+
+  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}`;
+}
+
+// Test cases
+console.log(toPounds("399p"));   // £3.99
+console.log(toPounds("5p"));     // £0.05
+console.log(toPounds("1200p"));  // £12.00
+
diff --git a/Sprint-2/4-mandatory-interpret/time-format.js b/Sprint-2/4-mandatory-interpret/time-format.js
index 7c98eb0e8..5511599fa 100644
--- a/Sprint-2/4-mandatory-interpret/time-format.js
+++ b/Sprint-2/4-mandatory-interpret/time-format.js
@@ -11,24 +11,21 @@ function formatTimeDisplay(seconds) {
   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
-
 // Questions
 
 // a) When formatTimeDisplay is called how many times will pad be called?
-// =============> write your answer here
+// =============> 3 times
 
 // 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
+// =============> 0 (the first call is pad(totalHours), and totalHours is 0 when seconds = 61)
 
-// 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" (0 becomes "0" then padStart(2,"0") makes it "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
+// d) What is the value assigned to num when pad is called for the last time in this program? Explain your answer
+// =============> 1 (the last call is pad(remainingSeconds), and 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
+// e) What is the return value assigned to num when pad is called for the last time in this program? Explain your answer
+// =============> "01" ("1" is padded to two digits using padStart)
\ No newline at end of file
diff --git a/Sprint-2/5-stretch-extend/format-time.js b/Sprint-2/5-stretch-extend/format-time.js
index 32a32e66b..9cc463c99 100644
--- a/Sprint-2/5-stretch-extend/format-time.js
+++ b/Sprint-2/5-stretch-extend/format-time.js
@@ -3,11 +3,17 @@
 // 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 hours24 = Number(time.slice(0, 2));
+  const minutes = time.slice(3, 5);
+
+  const period = hours24 >= 12 ? "pm" : "am";
+
+  let hours12 = hours24 % 12;
+  if (hours12 === 0) hours12 = 12;
+
+  const paddedHours12 = String(hours12).padStart(2, "0");
+
+  return `${paddedHours12}:${minutes} ${period}`;
 }
 
 const currentOutput = formatAs12HourClock("08:00");
@@ -23,3 +29,44 @@ console.assert(
   currentOutput2 === targetOutput2,
   `current output: ${currentOutput2}, target output: ${targetOutput2}`
 );
+
+
+
+// --------------------
+// Extra tests (edge cases + minutes)
+// --------------------
+
+// Midnight (00:00) should be 12:00 am
+console.assert(
+  formatAs12HourClock("00:00") === "12:00 am",
+  `current output: ${formatAs12HourClock("00:00")}, target output: 12:00 am`
+);
+
+// Noon (12:00) should be 12:00 pm
+console.assert(
+  formatAs12HourClock("12:00") === "12:00 pm",
+  `current output: ${formatAs12HourClock("12:00")}, target output: 12:00 pm`
+);
+
+// Minutes must be preserved
+console.assert(
+  formatAs12HourClock("23:15") === "11:15 pm",
+  `current output: ${formatAs12HourClock("23:15")}, target output: 11:15 pm`
+);
+
+console.assert(
+  formatAs12HourClock("13:05") === "01:05 pm",
+  `current output: ${formatAs12HourClock("13:05")}, target output: 01:05 pm`
+);
+
+// Morning should stay am
+console.assert(
+  formatAs12HourClock("01:09") === "01:09 am",
+  `current output: ${formatAs12HourClock("01:09")}, target output: 01:09 am`
+);
+
+// Boundary just before noon
+console.assert(
+  formatAs12HourClock("11:59") === "11:59 am",
+  `current output: ${formatAs12HourClock("11:59")}, target output: 11:59 am`
+);
\ No newline at end of file