diff --git a/.gitignore b/.gitignore
index bde36e530..ca75f83ac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 node_modules
 .DS_Store
 .vscode
+testing.js --- IGNORE ---
 **/.DS_Store
\ No newline at end of file
diff --git a/Sprint-2/1-key-errors/0.js b/Sprint-2/1-key-errors/0.js
index 653d6f5a0..1090b27dd 100644
--- a/Sprint-2/1-key-errors/0.js
+++ b/Sprint-2/1-key-errors/0.js
@@ -1,13 +1,24 @@
 // Predict and explain first...
-//  =============> write your prediction here
+// The code has a function that is supposed to capitalise the string passed to it. (only the first letter)
+// the string will be stored in the variable str and the function will return its value.
+// it takes the first letter (str[0]) and uses toUpperCase() method to capitalise it.
+// the str.slice(1) method is used to show the letter.
+// 
 
 // 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;
 }
 
 // =============> write your explanation here
+// an error occured because the variable str was already declared as a parameter of the function so
+// there was no need to use let again.
+
+
 // =============> write your new code here
+function capitalise(str) {
+  str = `${str[0].toUpperCase()}${str.slice(1)}`;
+  return str;
+}
+
+console.log(capitalise("hello"));
\ No newline at end of file
diff --git a/Sprint-2/1-key-errors/1.js b/Sprint-2/1-key-errors/1.js
index f2d56151f..9892dae5f 100644
--- a/Sprint-2/1-key-errors/1.js
+++ b/Sprint-2/1-key-errors/1.js
@@ -1,7 +1,11 @@
 // Predict and explain first...
+// the code is supposed to convert a decimal number to percentage by multiplying 
+// the decimal Number by 100 then add the sign % to show that it is a percentage
 
 // Why will an error occur when this program runs?
 // =============> write your prediction here
+// an error will occur because the variable decimalNumber is redeclared inside the function.
+// it's already declared as a parameter of the function, so redeclaring it with const causes a syntax error.
 
 // Try playing computer with the example to work out what is going on
 
@@ -15,6 +19,18 @@ function convertToPercentage(decimalNumber) {
 console.log(decimalNumber);
 
 // =============> write your explanation here
+// the fucntion convertToPercentage has a parameter named decimalNumber,
+// but inside the function, there is a line that tries to declare a new constant with the same name decimalNumber.
+// there is no need to redeclare the variable or edit it since it is a user input.
+// also the variable decimalNumber is called from outside the function which menas from another scope.
+// that is wrong because the variable can only be used inside the fucntion. instead of that we need to call the funtion, not hte variable.
 
 // 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(0.3));
\ 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..e95d45601 100644
--- a/Sprint-2/1-key-errors/2.js
+++ b/Sprint-2/1-key-errors/2.js
@@ -4,17 +4,32 @@
 // this function should square any number but instead we're going to get an error
 
 // =============> write your prediction of the error here
+// the error will occur because the parameter name is a number (3) which is not allowed.
+// it should be a variable or empty.
 
 function square(3) {
     return num * num;
 }
 
 // =============> write the error message here
-
+// SyntaxError: Unexpected number
+//     at internalCompileFunction (node:internal/vm:73:18)
+//     at wrapSafe (node:internal/modules/cjs/loader:1274:20)
+//     at Module._compile (node:internal/modules/cjs/loader:1320:27)
+//     at Module._extensions..js (node:internal/modules/cjs/loader:1414:10)
+//     at Module.load (node:internal/modules/cjs/loader:1197:32)
+//     at Module._load (node:internal/modules/cjs/loader:1013:12)
+//     at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:128:12)
+//     at node:internal/main/run_main_module:28:49
+
+// Node.js v18.19.1
 // =============> explain this error message here
-
+// ther error message says that a number can not put as an input when declaring the function
 // Finally, correct the code to fix the problem
 
 // =============> write your new code here
+function square(num) {
+    return num * num;
+}
 
-
+console.log(square(5));
diff --git a/Sprint-2/2-mandatory-debug/0.js b/Sprint-2/2-mandatory-debug/0.js
index b27511b41..3bcfca9bf 100644
--- a/Sprint-2/2-mandatory-debug/0.js
+++ b/Sprint-2/2-mandatory-debug/0.js
@@ -1,6 +1,7 @@
 // Predict and explain first...
-
 // =============> write your prediction here
+// this code will use the declared function multiplay (a, b) to multiply two numbers, 10 and 32, and print the result to the console. 
+// However, the function can not be used to get the result because it does not return any value. Instead, it only logs the result to the console.
 
 function multiply(a, b) {
   console.log(a * b);
@@ -9,6 +10,13 @@ function multiply(a, b) {
 console.log(`The result of multiplying 10 and 32 is ${multiply(10, 32)}`);
 
 // =============> write your explanation here
+// the function does not return any value, it only prints the result to the console, so it can't be used to return anything, it will return "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)}`);
\ 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..d91b81184 100644
--- a/Sprint-2/2-mandatory-debug/1.js
+++ b/Sprint-2/2-mandatory-debug/1.js
@@ -1,5 +1,7 @@
 // Predict and explain first...
 //  =============> write your prediction here
+// the function will throw an error because it does not return any value, the use of return without passing any value will cause an error.
+// also the last line of the function is unreachable because it comes after the return statement.
 
 function sum(a, b) {
   return;
@@ -9,5 +11,13 @@ function sum(a, b) {
 console.log(`The sum of 10 and 32 is ${sum(10, 32)}`);
 
 // =============> write your explanation here
+// The function will not return the expected sum because the return statement is not followed by any value.
+
 // 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..56a33f0d1 100644
--- a/Sprint-2/2-mandatory-debug/2.js
+++ b/Sprint-2/2-mandatory-debug/2.js
@@ -1,7 +1,15 @@
 // Predict and explain first...
+// the code should display the last digit of any number passed to the function.
+// but there is an error which is the variable num is globally declared and has a value of 103.
+// the function does not take any parameters, and it takes the global variable num which is always 103.
+// that causes the code to always return 3 as 3 is the last digit of 103 which is the value of the global variable num.
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// since 3 is the last digit of 103, I think the output will be:
+// The last digit of 42 is 3
+// The last digit of 105 is 3
+// The last digit of 806 is 3
 
 const num = 103;
 
@@ -14,11 +22,29 @@ 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 output is as I predicted.
+
 // =============> 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 the function getLastDigit does not take any parameters, and it uses the global variable num which is always 103.
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
+// no need to declare the global variable num here. instead, we will pass it as a parameter to the function.
+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 the function does not take the parameter so it will always use the variable num which is always 103.
\ 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..a8c508bdd 100644
--- a/Sprint-2/3-mandatory-implement/1-bmi.js
+++ b/Sprint-2/3-mandatory-implement/1-bmi.js
@@ -14,6 +14,13 @@
 // 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) {
+function calculateBmi(weight, height) {
     // return the BMI of someone based off their weight and height
-}
\ No newline at end of file
+    let squaredHeight = height * height;
+    let bmi = weight/squaredHeight;
+    bmi = bmi.toFixed(1);
+    return Number(bmi);
+}
+
+console.log(calculateBmi(70, 1.73));
+//console.log(calculateBmi(70, 1.73) + 5);
\ 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..810feb63f 100644
--- a/Sprint-2/3-mandatory-implement/2-cases.js
+++ b/Sprint-2/3-mandatory-implement/2-cases.js
@@ -14,3 +14,20 @@
 // 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(string)
+{
+    let output = '';
+    for(let i = 0; i < string.length; i++)
+    {
+        let char = string[i];
+        if(char === " ")
+        {
+            char = "_";
+        }
+        output += char;
+    }
+    return output.toUpperCase();
+}
+
+console.log(toUpperSnakeCase("Hello there, How are you doing guys?"));
diff --git a/Sprint-2/3-mandatory-implement/3-to-pounds.js b/Sprint-2/3-mandatory-implement/3-to-pounds.js
index 6265a1a70..787ffc088 100644
--- a/Sprint-2/3-mandatory-implement/3-to-pounds.js
+++ b/Sprint-2/3-mandatory-implement/3-to-pounds.js
@@ -4,3 +4,29 @@
 // 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("5764p"));
+console.log(toPounds("813p"));
+console.log(toPounds("90897867564p"));
+console.log(toPounds("71p"));
+console.log(toPounds("312987p"));
\ No newline at end of file
diff --git a/Sprint-2/4-mandatory-interpret/time-format.js b/Sprint-2/4-mandatory-interpret/time-format.js
index 7c98eb0e8..4d278fa7c 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)}`;
 }
 
+console.log(formatTimeDisplay(61));
 // 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 +19,23 @@ function formatTimeDisplay(seconds) {
 
 // a) When formatTimeDisplay is called how many times will pad be called?
 // =============> write your answer here
+// The function pad will be called 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
+// the value is 0
 
 // c) What is the return value of pad is called for the first time?
 // =============> write your answer here
+// # The Python visualizer stops working when it runs pad because (padStart is not a function), maybe because it uses ES6 version of javascript!
+// The return value of pad when it's called for the first time is String "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
+//the value assigned to num is 1 . the value 1 is the number of the remaining seconds, pad() converted it to 01 
 
 // 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
+// the return value is 01 . the function pad() converted num (which values 1) to 01 so the seconds can be readable easily.
\ 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..7978b5a62 100644
--- a/Sprint-2/5-stretch-extend/format-time.js
+++ b/Sprint-2/5-stretch-extend/format-time.js
@@ -3,23 +3,60 @@
 // 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 `${hours - 12}:00 pm`;
+  let hours = Number(time.slice(0, 2));
+  let minutes= time.slice(3, 5);
+  let timeIndicator;
+
+  if (hours >= 12) {
+    hours = hours - 12;
+    timeIndicator = "pm";
+  } else {
+    timeIndicator = "am";
   }
-  return `${time} am`;
+  if ( hours === 0)
+    hours = 12;
+
+  return `${String(hours).padStart(2, "0")}:${minutes} ${timeIndicator}`;
 }
 
-const currentOutput = formatAs12HourClock("08:00");
-const targetOutput = "08:00 am";
+let currentOutput = formatAs12HourClock("14:00");
+let targetOutput = "02:00 pm";
 console.assert(
   currentOutput === targetOutput,
   `current output: ${currentOutput}, target output: ${targetOutput}`
 );
-
-const currentOutput2 = formatAs12HourClock("23:00");
-const targetOutput2 = "11:00 pm";
+//==========================
+currentOutput = formatAs12HourClock("23:00");
+targetOutput = "11:00 pm";
+console.assert(
+  currentOutput === targetOutput,
+  `current output: ${currentOutput}, target output: ${targetOutput}`
+);
+//==========================
+currentOutput = formatAs12HourClock("07:51");
+targetOutput = "07:51 am";
+console.assert(
+  currentOutput === targetOutput,
+  `current output: ${currentOutput}, target output: ${targetOutput}`
+);
+//==========================
+currentOutput = formatAs12HourClock("00:37");
+targetOutput = "12:37 am";
 console.assert(
-  currentOutput2 === targetOutput2,
-  `current output: ${currentOutput2}, target output: ${targetOutput2}`
+  currentOutput === targetOutput,
+  `current output: ${currentOutput}, target output: ${targetOutput}`
+);
+//==========================
+currentOutput = formatAs12HourClock("12:37");
+targetOutput = "12:37 pm";
+console.assert(
+  currentOutput === targetOutput,
+  `current output: ${currentOutput}, target output: ${targetOutput}`
+);
+//==========================
+currentOutput = formatAs12HourClock("20:59");
+targetOutput = "08:59 pm";
+console.assert(
+  currentOutput === targetOutput,
+  `current output: ${currentOutput}, target output: ${targetOutput}`
 );
diff --git a/testing.js b/testing.js
new file mode 100644
index 000000000..146392abf
--- /dev/null
+++ b/testing.js
@@ -0,0 +1,23 @@
+function formatAs12HourClock(time) {
+  if (Number(time.slice(0, 2)) > 12)
+  {
+    return `${Number(time.slice(0, 2) - 12)}:00 pm`;
+  }
+  return `${time} am`;
+}
+
+let targetOutPut = "2:00 pm";
+let currentOutPut= formatAs12HourClock("14:00");
+
+console.assert(
+  targetOutPut === currentOutPut,
+  `current output: ${currentOutPut}, target output: ${targetOutPut}`
+);
+// =========
+targetOutPut = "11:00 am";
+currentOutPut= formatAs12HourClock("11:00");
+
+console.assert(
+  currentOutPut === targetOutPut,
+  `Error,, current is ${currentOutPut} and target is ${targetOutPut}`
+);
\ No newline at end of file