diff --git a/Sprint-3/1-key-errors/0.js b/Sprint-3/1-key-errors/0.js
index 653d6f5a0..4b8adb940 100644
--- a/Sprint-3/1-key-errors/0.js
+++ b/Sprint-3/1-key-errors/0.js
@@ -1,13 +1,32 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// capitalise function takes 1 str arg
+// let srting will give an error if i try to pass my string.
+// remove let 
+// str is being put in template literal
+// str[0]: 1st index of str becomes uppercase
+// str.slice(1): 2nd index slice until end of str
+// str = "frankocean"
+// return = "Frankocean"
+
 
 // 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
+// let str = `${str[0].toUpperCase()}${str.slice(1)}`;
+// I was right, error given is because of let str within the function. 
+// SyntaxError: Identifier 'str' has already been declared 
+// We cannot have two declarations of the same variable so we remove the let inside .capitalise.
 // =============> write your new code here
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}
+console.log(capitalise("frankocean"))
diff --git a/Sprint-3/1-key-errors/1.js b/Sprint-3/1-key-errors/1.js
index f2d56151f..66901d730 100644
--- a/Sprint-3/1-key-errors/1.js
+++ b/Sprint-3/1-key-errors/1.js
@@ -2,19 +2,33 @@
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// decimalNumber declared inside the function, this is the value that must be an arg
+// line 17 also fails because it tries to access a var that is declared within the function
 
 // Try playing computer with the example to work out what is going on
 
-function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
-  const percentage = `${decimalNumber * 100}%`;
+// function convertToPercentage(decimalNumber) {
+//   const decimalNumber = 0.5;
+//   const percentage = `${decimalNumber * 100}%`;
 
-  return percentage;
-}
+//   return percentage;
+// }
 
-console.log(decimalNumber);
+// console.log(decimalNumber);
 
 // =============> write your explanation here
+// Remove the local var declaration
+// ReferenceError: decimalNumber is not defined | console.log(decimalNumber);
+// define decimalNumber in line 17 by passing the function with decimalNumber value
+// remove the definition in line 11
 
 // 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-3/1-key-errors/2.js b/Sprint-3/1-key-errors/2.js
index aad57f7cf..1e01ecb9b 100644
--- a/Sprint-3/1-key-errors/2.js
+++ b/Sprint-3/1-key-errors/2.js
@@ -4,17 +4,25 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// Error because 3 is a value, functions take parameters(like num). 
+// It wont work 3 is a number literal and not a name/identifier.
 
-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 code was expecting the parameter name but found the number literal =3
+// This is why we get the syntax error.
 
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
+function square(num) {
+    return num * num;
+}
 
-
+console.log(square(3));
\ No newline at end of file
diff --git a/Sprint-3/2-mandatory-debug/0.js b/Sprint-3/2-mandatory-debug/0.js
index b27511b41..4307eeac4 100644
--- a/Sprint-3/2-mandatory-debug/0.js
+++ b/Sprint-3/2-mandatory-debug/0.js
@@ -1,14 +1,26 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// It will print 2 lines:
+// (10*32=320) line 1: 320
+// line 2: 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
+// There are two console.log() being called.
+// The one inside the funtion prints the result of the multiplication
+// The one outside the function prints the desired result of the whole string but there is no return from the function so it is undefined
+// 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-3/2-mandatory-debug/1.js b/Sprint-3/2-mandatory-debug/1.js
index 37cedfbcf..cf860db05 100644
--- a/Sprint-3/2-mandatory-debug/1.js
+++ b/Sprint-3/2-mandatory-debug/1.js
@@ -1,13 +1,24 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// I dont think the code will run at all since the return is separated from the sum that should happen
+// the console.log() oustide the function will say the sum is undefined.
 
-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 of 10 and 32 is undefined
+// I was wrong, I thought that the code would not run.
+// The output says the sum is undefined because the return statement and the "a + b" are separated by ; 
+// To fix it, I just need to remove the ; next to return on line 7.
 // 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-3/2-mandatory-debug/2.js b/Sprint-3/2-mandatory-debug/2.js
index 57d3f5dc3..726549eb8 100644
--- a/Sprint-3/2-mandatory-debug/2.js
+++ b/Sprint-3/2-mandatory-debug/2.js
@@ -2,23 +2,44 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// Nothing is going to run properly because the function does not have any parameters.
+// I think everything will get a syntax error
 
-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
+// I was wrong in my prediction. Code runs.
+// It says the last digit is 3 for every number which is wrong
+// This is because we declared the var num = 103 globally, and it is affecting all the fucntion calls
+// Because of the global declaration, every function call is going to use the global num 
+// This is bad because the code is now taking in diferent parameters but returning a value based on one global value.
+// TO fix this we remove the global var num.
+// Then we add num as a parameter in the function :getLastDigit(num)
+
 // 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-3/3-mandatory-implement/1-bmi.js b/Sprint-3/3-mandatory-implement/1-bmi.js
index 58b1085f1..eded36a45 100644
--- a/Sprint-3/3-mandatory-implement/1-bmi.js
+++ b/Sprint-3/3-mandatory-implement/1-bmi.js
@@ -16,4 +16,6 @@
 
 function calculateBMI(weight, height) {
   // return the BMI of someone based off their weight and height
+  return  (weight / (height * height)).toFixed(1)
 }
+console.log(calculateBMI(70, 1.73))
\ No newline at end of file
diff --git a/Sprint-3/3-mandatory-implement/2-cases.js b/Sprint-3/3-mandatory-implement/2-cases.js
index 5b0ef77ad..943eabf25 100644
--- a/Sprint-3/3-mandatory-implement/2-cases.js
+++ b/Sprint-3/3-mandatory-implement/2-cases.js
@@ -14,3 +14,10 @@
 // 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 UPPER_SNAKE_CASE(str) {
+    let snake_case = str.replaceAll(" ", "_");
+    return snake_case.toUpperCase()
+}
+
+console.log(UPPER_SNAKE_CASE("have you ever had a krispy kreme"))
\ No newline at end of file
diff --git a/Sprint-3/3-mandatory-implement/3-to-pounds.js b/Sprint-3/3-mandatory-implement/3-to-pounds.js
index 10754da73..a7f3178d4 100644
--- a/Sprint-3/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-3/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,16 @@
 // 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(str) {
+    let penceStringWithoutTrailingP = str.substring(0, str.length - 1);
+
+    let paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+    let pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2);
+
+    let pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0");
+
+    console.log(`£${pounds}.${pence}`);
+}
+
+toPounds("5045p")
\ No newline at end of file
diff --git a/Sprint-3/4-mandatory-interpret/time-format.js b/Sprint-3/4-mandatory-interpret/time-format.js
index c0dd9c9a5..f53bec84e 100644
--- a/Sprint-3/4-mandatory-interpret/time-format.js
+++ b/Sprint-3/4-mandatory-interpret/time-format.js
@@ -7,10 +7,10 @@ function pad(num) {
 }
 
 function formatTimeDisplay(seconds) {
-  const remainingSeconds = seconds % 60;
-  const totalMinutes = (seconds - remainingSeconds) / 60;
-  const remainingMinutes = totalMinutes % 60;
-  const totalHours = (totalMinutes - remainingMinutes) / 60;
+  const remainingSeconds = seconds % 60; // 1
+  const totalMinutes = (seconds - remainingSeconds) / 60; // 1
+  const remainingMinutes = totalMinutes % 60; // 1
+  const totalHours = (totalMinutes - remainingMinutes) / 60; //0
 
   return `${pad(totalHours)}:${pad(remainingMinutes)}:${pad(remainingSeconds)}`;
 }
@@ -21,18 +21,18 @@ function formatTimeDisplay(seconds) {
 // 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:
-
+console.log(formatTimeDisplay(61)) // 00:01:01
 // b) What is the value assigned to num when pad is called for the first time?
-// =============> write your answer here
+// 0
 
 // c) What is the return value of pad when it is called for the first time?
-// =============> write your answer here
+// "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
+// 1
 
 // e) What is the return value of pad when it is called for the last time in this program?  Explain your answer
-// =============> write your answer here
+// "01"
diff --git a/Sprint-3/5-stretch-extend/format-time.js b/Sprint-3/5-stretch-extend/format-time.js
index 32a32e66b..f7609b09f 100644
--- a/Sprint-3/5-stretch-extend/format-time.js
+++ b/Sprint-3/5-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.
 
+// original code:
+// 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: ${targetOutput2}`
+// );
+
+// my code:
 function formatAs12HourClock(time) {
   const hours = Number(time.slice(0, 2));
-  if (hours > 12) {
-    return `${hours - 12}:00 pm`;
+  if (hours >= 12) {
+    return `${hours - 12}:${time.slice(3)} pm`;
   }
-  return `${time} am`;
+  return `${time}:${time.slice(3)} am`;
 }
 
-const currentOutput = formatAs12HourClock("08:00");
-const targetOutput = "08:00 am";
-console.assert(
-  currentOutput === targetOutput,
-  `current output: ${currentOutput}, target output: ${targetOutput}`
-);
+const cases = [
+  { input: "00:00", expected: "12:00 am" },  // midnight
+  { input: "01:00", expected: "01:00 am" },
+  { input: "02:00", expected: "02:00 am" },  // your failing test
+  { input: "09:00", expected: "09:00 am" },
+  { input: "11:59", expected: "11:59 am" },
+  { input: "12:00", expected: "12:00 pm" },  // noon
+  { input: "12:30", expected: "12:30 pm" },
+  { input: "13:00", expected: "01:00 pm" },
+  { input: "23:00", expected: "11:00 pm" },  // your other test
+  { input: "23:59", expected: "11:59 pm" },
+];
 
-const currentOutput2 = formatAs12HourClock("23:00");
-const targetOutput2 = "11:00 pm";
-console.assert(
-  currentOutput2 === targetOutput2,
-  `current output: ${currentOutput2}, target output: ${targetOutput2}`
-);
+function runTests(cases) {
+  let passed = 0;
+  for (const { input, expected } of cases) {
+    const actual = formatAs12HourClock(input);
+    const ok = actual === expected;
+    if (ok) passed++;
+    console.log(
+      `${ok ? "PASS" : "FAIL"}  input: ${input}  expected: ${expected}  actual: ${actual}`
+    );
+  }
+  console.log(`\n${passed}/${cases.length} passed`);
+}
+runTests(cases);
\ No newline at end of file