diff --git a/Project-CLI-Treasure-Hunt b/Project-CLI-Treasure-Hunt
new file mode 160000
index 000000000..6668c42dc
--- /dev/null
+++ b/Project-CLI-Treasure-Hunt
@@ -0,0 +1 @@
+Subproject commit 6668c42dc5412e54026ca0fa8cb5691017ef6350
diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
index 653d6f5a0..194714664 100644
--- a/Sprint-2/1-key-errors/0.js
+++ b/Sprint-2/1-key-errors/0.js
@@ -1,13 +1,18 @@
 // Predict and explain first...
 //  =============> write your prediction here
-
+// I gives us a syntax error as str declared before.
 // 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 explanation here :
+// as the variable in side the function has the same name as the function variable.
 // =============> write your new code here
+function capitalise(str) {
+  return `${str[0].toUpperCase()}${str.slice(1)}`;
+}
+console.log(capitalise("abcd"));
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
index f2d56151f..be26e66f2 100644
--- a/Sprint-2/1-key-errors/1.js
+++ b/Sprint-2/1-key-errors/1.js
@@ -1,20 +1,30 @@
 // Predict and explain first...
-
-// Why will an error occur when this program runs?
+// error on line 11
+// error on line 17
+// Why will an error occur when this program runs? yes
 // =============> write your prediction here
+// decimalNumber is declared before and can not be declared again.
+// console.log(decimalNumber) should be console.log(convertToPercentage)
+// Try playing computer with the example to work ot what is going on
 
-// 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(percentage);
 
 // =============> write your explanation here
+// decimalNumber is declared before and can not be declared again.
+// console.log(decimalNumber) should be console.log(convertToPercentage)
 
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+function convertToPercentage(decimalNumber) {
+  return `${decimalNumber * 100}%`;
+
+}
+
+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..3e633b725 100644
--- a/Sprint-2/1-key-errors/2.js
+++ b/Sprint-2/1-key-errors/2.js
@@ -4,17 +4,21 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// line 9 num is not defined.
 
-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
-
+// 3 is not a variable for the function to use. It should be a variable name like num or n.
 // 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..7fcd67dfe 100644
--- a/Sprint-2/2-mandatory-debug/0.js
+++ b/Sprint-2/2-mandatory-debug/0.js
@@ -1,14 +1,20 @@
 // Predict and explain first...
 
 // =============> write your prediction here
+// it looks fine. 
 
-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
-
+// It misses the return value of multiply function.
 // 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)}`);
\ No newline at end of file
diff --git a/Sprint-2/2-mandatory-debug/1.js b/Sprint-2/2-mandatory-debug/1.js
index 37cedfbcf..6147695e4 100644
--- a/Sprint-2/2-mandatory-debug/1.js
+++ b/Sprint-2/2-mandatory-debug/1.js
@@ -1,13 +1,19 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// there is an error on line 5 and 6  
+//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 not returning any value. a+b mentioned after return.
 // 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..986d3753b 100644
--- a/Sprint-2/2-mandatory-debug/2.js
+++ b/Sprint-2/2-mandatory-debug/2.js
@@ -2,23 +2,35 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// the result will be 3 
+// 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
+// because num is defined as 103 and not taking any input from the function parameter.
 // 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
+// because num is defined as 103 and not taking any input from the function parameter.
\ No newline at end of file
diff --git a/Sprint-2/2-mandatory-debug/new.js b/Sprint-2/2-mandatory-debug/new.js
new file mode 100644
index 000000000..e69de29bb
diff --git a/Sprint-2/3-mandatory-implement/1-bmi.js b/Sprint-2/3-mandatory-implement/1-bmi.js
index 17b1cbde1..a88f4fa2e 100644
--- a/Sprint-2/3-mandatory-implement/1-bmi.js
+++ b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -16,4 +16,7 @@
 
 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); 
+}
+console.log(`The BMI of a person weighing 70kg and 1.73m tall is ${calculateBMI(70, 1.73)}`);  
\ 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..07274a51f 100644
--- a/Sprint-2/3-mandatory-implement/2-cases.js
+++ b/Sprint-2/3-mandatory-implement/2-cases.js
@@ -14,3 +14,8 @@
 // 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.toUpperCase().replace(/ /g, '_');
+}
+console.log(toUpperSnakeCase("it's done!"));
\ 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..5e2fdf1b7 100644
--- a/Sprint-2/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-2/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,25 @@
 // 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}`;
+}
+console.log(toPounds("399p"));
+console.log(toPounds("50p"));
+console.log(toPounds("5p"));
+console.log(toPounds("0p"));
+console.log(toPounds("12345p"));
diff --git a/Sprint-2/4-mandatory-interpret/time-format.js b/Sprint-2/4-mandatory-interpret/time-format.js
index 7c98eb0e8..8afb1df79 100644
--- a/Sprint-2/4-mandatory-interpret/time-format.js
+++ b/Sprint-2/4-mandatory-interpret/time-format.js
@@ -11,6 +11,7 @@ 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
 
@@ -18,17 +19,20 @@ function formatTimeDisplay(seconds) {
 
 // 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));
 
 // 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 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, because remainingSeconds is 1 when pad is called for the last time.
 // 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
+// "01", because pad adds a leading zero to single digit numbers.
\ 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..970f590fa 100644
--- a/Sprint-2/5-stretch-extend/format-time.js
+++ b/Sprint-2/5-stretch-extend/format-time.js
@@ -2,24 +2,42 @@
 // 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 `${hours - 12}:00 pm`;
+
+if (!/^\d{2}:\d{2}$/.test(time)) {
+    return "Invalid time format";
+  } 
+
+const hours = Number(time.slice(0, 2));
+const minutes = Number(time.slice(3, 5));
+if (hours < 0 || hours > 23 || minutes < 0 || minutes > 59) {
+    return "Invalid time range";
   }
-  return `${time} am`;
-}
+  let period = "am";
+  let displayHours = hours;
 
-const currentOutput = formatAs12HourClock("08:00");
-const targetOutput = "08:00 am";
-console.assert(
-  currentOutput === targetOutput,
-  `current output: ${currentOutput}, target output: ${targetOutput}`
-);
+  if (hours === 0) {
+    displayHours = 12; // midnight
+  } else if (hours === 12) {
+    period = "pm"; // noon
+  } else if (hours > 12) {
+    displayHours = hours - 12;
+    period = "pm";
+  }
+  const formattedHours = String(displayHours).padStart(2, "0");
+  const formattedMinutes = String(minutes).padStart(2, "0");
+  return `${formattedHours}:${formattedMinutes} ${period}`;
+}
+console.log(formatAs12HourClock("00:00"));
 
-const currentOutput2 = formatAs12HourClock("23:00");
-const targetOutput2 = "11:00 pm";
-console.assert(
-  currentOutput2 === targetOutput2,
-  `current output: ${currentOutput2}, target output: ${targetOutput2}`
-);
+console.assert(formatAs12HourClock("00:00") === "12:00 am", "Midnight");
+console.assert(formatAs12HourClock("12:00") === "12:00 pm", "Noon");
+console.assert(formatAs12HourClock("08:30") === "08:30 am", "Morning");
+console.assert(formatAs12HourClock("15:45") === "03:45 pm", "Afternoon");
+console.assert(formatAs12HourClock("23:59") === "11:59 pm", "Late night");
+console.assert(formatAs12HourClock("24:00") === "Invalid time range", "Hour too high");
+console.assert(formatAs12HourClock("12:60") === "Invalid time range", "Minute too high");
+console.assert(formatAs12HourClock("8:7") === "Invalid time format", "Wrong format");
+console.assert(formatAs12HourClock("hello") === "Invalid time format", "Not a time");
\ No newline at end of file