diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
index 653d6f5a0..f6647cd35 100644
--- a/Sprint-2/1-key-errors/0.js
+++ b/Sprint-2/1-key-errors/0.js
@@ -1,5 +1,5 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  we can not declare a variable which has the same name as the parameter, we will get a SyntaxError
 
 // call the function capitalise with a string input
 // interpret the error message and figure out why an error is occurring
@@ -8,6 +8,7 @@ function capitalise(str) {
   let str = `${str[0].toUpperCase()}${str.slice(1)}`;
   return str;
 }
+console.log(capitalise("hello"))
 
-// =============> write your explanation here
-// =============> write your new code here
+// we are getting an error because of the way the function was wrote, "str" is the part that is causing the issue
+// we can not declare a variable which has the same name as the parameter
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
index f2d56151f..bba140804 100644
--- a/Sprint-2/1-key-errors/1.js
+++ b/Sprint-2/1-key-errors/1.js
@@ -1,20 +1,27 @@
 // Predict and explain first...
 
 // Why will an error occur when this program runs?
-// =============> write your prediction here
+// decimalNumber is already used as a parameter so it can not be used as a variable inside the function,
+// the code is logging the parameter instead 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 = `${decimalNumber * 100}%`;
+
+//   return percentage;
+// }
+
+// console.log(decimalNumber);
+
+// I'm not sure about what to write here
+
+// Finally, correct the code to fix the problem
 function convertToPercentage(decimalNumber) {
-  const decimalNumber = 0.5;
   const percentage = `${decimalNumber * 100}%`;
 
   return percentage;
 }
 
-console.log(decimalNumber);
-
-// =============> write your explanation here
-
-// Finally, correct the code to fix the problem
-// =============> write your new code here
+console.log(convertToPercentage(0.9))
diff --git a/Sprint-2/1-key-errors/2.js b/Sprint-2/1-key-errors/2.js
index aad57f7cf..98a54e4e7 100644
--- a/Sprint-2/1-key-errors/2.js
+++ b/Sprint-2/1-key-errors/2.js
@@ -3,18 +3,29 @@
 
 // this function should square any number but instead we're going to get an error
 
-// =============> write your prediction of the error here
+// undefined, because "num" isn't used as a parameter
 
-function square(3) {
-    return num * num;
-}
+// function square(3) {
+//     return num * num;
+// }
+
+// /Users/cyf/Desktop/CYF/Module-Structuring-and-Testing-Data/Sprint-2/1-key-errors/2.js:8
+// function square(3) {
+//     ^
 
-// =============> write the error message here
+// SyntaxError: Unexpected number
 
-// =============> explain this error message here
+
+// the first line tells us where the error occurs:root,folder,file,line 
+//second line shows exactly which piece of code throws the error
+//third line tells us which type of error it is, in this case it is a SyntaxError, meaning that the code wasnt written according to the rules of js,
+//an finally it tells us what went wrong
 
 // 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..9f9781d9c 100644
--- a/Sprint-2/2-mandatory-debug/0.js
+++ b/Sprint-2/2-mandatory-debug/0.js
@@ -1,14 +1,18 @@
 // Predict and explain first...
 
-// =============> write your prediction here
+// the function hasn't got a return so the log will be 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
+// the function hasn't got a return so the log will be 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..7eeb632af 100644
--- a/Sprint-2/2-mandatory-debug/1.js
+++ b/Sprint-2/2-mandatory-debug/1.js
@@ -1,13 +1,18 @@
 // Predict and explain first...
-//  =============> write your prediction here
+//  SyntaxError
 
+// function sum(a, b) {
+//   return;
+//   a + b;
+// }
+
+// console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
+
+// the function doesn't return anything because there is ";" immediately after "return" and the mathematicall operation is on another line
+// Finally, correct the code to fix the problem
 function sum(a, b) {
-  return;
-  a + b;
+  return a + b;
+  
 }
 
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
-
-// =============> write your explanation here
-// Finally, correct the code to fix the problem
-//  =============> write your new code here
diff --git a/Sprint-2/2-mandatory-debug/2.js b/Sprint-2/2-mandatory-debug/2.js
index 57d3f5dc3..3dbb912c8 100644
--- a/Sprint-2/2-mandatory-debug/2.js
+++ b/Sprint-2/2-mandatory-debug/2.js
@@ -1,11 +1,27 @@
 // Predict and explain first...
 
 // Predict the output of the following code:
-// =============> Write your prediction here
+// num undefined
 
-const num = 103;
+// const num = 103;
 
-function getLastDigit() {
+// 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
+// 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
+// because num is declared as a global variable and it never changes, should be used as parameter
+// Finally, correct the code to fix the problem
+ function getLastDigit(num) {
   return num.toString().slice(-1);
 }
 
@@ -13,12 +29,5 @@ 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
-// Explain why the output is the way it is
-// =============> write your explanation here
-// 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
diff --git a/Sprint-2/3-mandatory-implement/1-bmi.js b/Sprint-2/3-mandatory-implement/1-bmi.js
index 17b1cbde1..ab4db0920 100644
--- a/Sprint-2/3-mandatory-implement/1-bmi.js
+++ b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -15,5 +15,15 @@
 // 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
+    let sqh=height*height;
+    let bmi=weight/sqh;
+    let bmiS=bmi.toString()
+    
+    
+    if(bmiS.includes(".")){
+        let dotBmiS=bmiS.indexOf(".")
+        return (Number(bmiS.slice(0,dotBmiS+2)))
+    } return bmi
+  
+}
+console.log(calculateBMI(20,1.79));
diff --git a/Sprint-2/3-mandatory-implement/2-cases.js b/Sprint-2/3-mandatory-implement/2-cases.js
index 5b0ef77ad..017f84176 100644
--- a/Sprint-2/3-mandatory-implement/2-cases.js
+++ b/Sprint-2/3-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 convertToSnakeUpperCase(str){
+    // const upper=str.toUpperCase();
+    // const snake=upper.replace(" ","_");
+    return str.toUpperCase().replaceAll(" ", "_");
+}
+console.log(convertToSnakeUpperCase("hello there buddy"));
diff --git a/Sprint-2/3-mandatory-implement/3-to-pounds.js b/Sprint-2/3-mandatory-implement/3-to-pounds.js
index 6265a1a70..476673a3c 100644
--- a/Sprint-2/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-2/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,23 @@
 // 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
+//const penceString = "399p";
+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("23354p"));
+console.log(toPounds("39p"));
+console.log(toPounds("9p"));
diff --git a/Sprint-2/4-mandatory-interpret/time-format.js b/Sprint-2/4-mandatory-interpret/time-format.js
index 7c98eb0e8..dbcad9e7f 100644
--- a/Sprint-2/4-mandatory-interpret/time-format.js
+++ b/Sprint-2/4-mandatory-interpret/time-format.js
@@ -17,18 +17,20 @@ 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:
 
 // 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=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
+// "01",remainingSeconds.toString().padStart(2, "0");
+
+
diff --git a/Sprint-2/5-stretch-extend/format-time.js b/Sprint-2/5-stretch-extend/format-time.js
index 32a32e66b..47283a7ac 100644
--- a/Sprint-2/5-stretch-extend/format-time.js
+++ b/Sprint-2/5-stretch-extend/format-time.js
@@ -4,8 +4,15 @@
 
 function formatAs12HourClock(time) {
   const hours = Number(time.slice(0, 2));
+  const minutes=time.slice(3,5)
+  if(hours<1){
+    return `12:${minutes} am`
+  }
+  if(hours==12 && minutes==00){
+    return "12:00 pm"
+  }
   if (hours > 12) {
-    return `${hours - 12}:00 pm`;
+    return `${hours - 12}:${minutes} pm`;
   }
   return `${time} am`;
 }
@@ -23,3 +30,34 @@ console.assert(
   currentOutput2 === targetOutput2,
   `current output: ${currentOutput2}, target output: ${targetOutput2}`
 );
+
+const currentOutput3 = formatAs12HourClock("23:33");
+const targetOutput3 = "11:33 pm";
+console.assert(
+  currentOutput3 === targetOutput3,
+  `current output: ${currentOutput3}, target output: ${targetOutput3}`
+);
+
+const currentOutput4 = formatAs12HourClock("11:59");
+const targetOutput4 = "11:59 am";
+console.assert(
+  currentOutput4 === targetOutput4,
+  `current output: ${currentOutput4}, target output: ${targetOutput4}`
+);
+
+const currentOutput5 = formatAs12HourClock("00:01");
+const targetOutput5 = "12:01 am";
+console.assert(
+  currentOutput5 === targetOutput5,
+  `current output: ${currentOutput5}, target output: ${targetOutput5}`
+);
+
+const currentOutput6 = formatAs12HourClock("12:00");
+const targetOutput6 = "12:00 pm";
+console.assert(
+  currentOutput6 === targetOutput6,
+  `current output: ${currentOutput6}, target output: ${targetOutput6}`
+);
+
+
+