diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js
index 117bcb2b6e..dddab4412b 100644
--- a/Sprint-1/1-key-exercises/1-count.js
+++ b/Sprint-1/1-key-exercises/1-count.js
@@ -4,3 +4,6 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+
+// [ChunYanWong] It is used to increse the value of the variable by 1
+
diff --git a/Sprint-1/1-key-exercises/2-initials.js b/Sprint-1/1-key-exercises/2-initials.js
index 47561f6175..2a716926ea 100644
--- a/Sprint-1/1-key-exercises/2-initials.js
+++ b/Sprint-1/1-key-exercises/2-initials.js
@@ -8,4 +8,5 @@ let lastName = "Johnson";
 let initials = ``;
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
-
+// added by ChunYanWong for the solution
+initials = firstName.substring(0,1) + middleName.substring(0,1) + lastName.substring(0,1);
diff --git a/Sprint-1/1-key-exercises/3-paths.js b/Sprint-1/1-key-exercises/3-paths.js
index ab90ebb28e..1d0f61c7a8 100644
--- a/Sprint-1/1-key-exercises/3-paths.js
+++ b/Sprint-1/1-key-exercises/3-paths.js
@@ -17,7 +17,7 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.substring(0, url.lastIndexOf("/") + 1);;
+const ext = filePath.substring(filePath.lastIndexOf('.') + 1);
 
-// https://www.google.com/search?q=slice+mdn
\ No newline at end of file
+// https://www.google.com/search?q=slice+mdn
diff --git a/Sprint-1/1-key-exercises/4-random.js b/Sprint-1/1-key-exercises/4-random.js
index 292f83aabb..6c83c30f87 100644
--- a/Sprint-1/1-key-exercises/4-random.js
+++ b/Sprint-1/1-key-exercises/4-random.js
@@ -7,3 +7,5 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+// [ChunYanWong] num is the random integer number generated in the range of 1 and 100 inclusively 
diff --git a/Sprint-1/2-mandatory-errors/0.js b/Sprint-1/2-mandatory-errors/0.js
index cf6c5039f7..e6b744a05b 100644
--- a/Sprint-1/2-mandatory-errors/0.js
+++ b/Sprint-1/2-mandatory-errors/0.js
@@ -1,2 +1,2 @@
-This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
\ No newline at end of file
+//This is just an instruction for the first activity - but it is just for human consumption
+//We don't want the computer to run these 2 lines - how can we solve this problem?
diff --git a/Sprint-1/2-mandatory-errors/1.js b/Sprint-1/2-mandatory-errors/1.js
index 7a43cbea76..031839b47d 100644
--- a/Sprint-1/2-mandatory-errors/1.js
+++ b/Sprint-1/2-mandatory-errors/1.js
@@ -1,4 +1,4 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
+let age = 33;
 age = age + 1;
diff --git a/Sprint-1/2-mandatory-errors/2.js b/Sprint-1/2-mandatory-errors/2.js
index e09b89831d..075984f569 100644
--- a/Sprint-1/2-mandatory-errors/2.js
+++ b/Sprint-1/2-mandatory-errors/2.js
@@ -1,5 +1,4 @@
 // Currently trying to print the string "I was born in Bolton" but it isn't working...
 // what's the error ?
-
-console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+console.log(`I was born in ${cityOfBirth}`);
diff --git a/Sprint-1/2-mandatory-errors/3.js b/Sprint-1/2-mandatory-errors/3.js
index ec101884db..c271de68df 100644
--- a/Sprint-1/2-mandatory-errors/3.js
+++ b/Sprint-1/2-mandatory-errors/3.js
@@ -1,5 +1,5 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+//const last4Digits = cardNumber.slice(-4);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
@@ -7,3 +7,8 @@ const last4Digits = cardNumber.slice(-4);
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+// [ChunYanWong] The slice method extract substring starting with the first parameter position
+// There is no -4 starting position and hence it will not work
+
+const last4Digits = cardNumber.slice(cardNumber.length - 4)
diff --git a/Sprint-1/2-mandatory-errors/4.js b/Sprint-1/2-mandatory-errors/4.js
index 5f86c730bc..8f04f980ad 100644
--- a/Sprint-1/2-mandatory-errors/4.js
+++ b/Sprint-1/2-mandatory-errors/4.js
@@ -1,2 +1,2 @@
-const 12HourClockTime = "8:53pm";
-const 24hourClockTime = "20:53";
+const twelveHourClockTime = "8:53pm";
+const twentyhourClockTime = "20:53";
diff --git a/Sprint-1/3-mandatory-interpret/1-percentage-change.js b/Sprint-1/3-mandatory-interpret/1-percentage-change.js
index e24ecb8e18..c839ff7f5c 100644
--- a/Sprint-1/3-mandatory-interpret/1-percentage-change.js
+++ b/Sprint-1/3-mandatory-interpret/1-percentage-change.js
@@ -2,7 +2,7 @@ let carPrice = "10,000";
 let priceAfterOneYear = "8,543";
 
 carPrice = Number(carPrice.replaceAll(",", ""));
-priceAfterOneYear = Number(priceAfterOneYear.replaceAll("," ""));
+priceAfterOneYear = Number(priceAfterOneYear.replaceAll(",", ""));
 
 const priceDifference = carPrice - priceAfterOneYear;
 const percentageChange = (priceDifference / carPrice) * 100;
@@ -12,11 +12,16 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+//[ChunYanWong] 3 . They are Number, replaceAll and console.log
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+// [ChunYanWong] syntax error - add the comma to fix it.
 
 // c) Identify all the lines that are variable reassignment statements
+// [ChunYanWong] line 4 and 5
 
 // d) Identify all the lines that are variable declarations
+// [ChunYanWong] line 1,2,7 and 8
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// [ChunYanWong] remove the comma for the amounts so that they can be converted to numbers for calculation 
diff --git a/Sprint-1/3-mandatory-interpret/2-time-format.js b/Sprint-1/3-mandatory-interpret/2-time-format.js
index 47d2395587..8f76676d06 100644
--- a/Sprint-1/3-mandatory-interpret/2-time-format.js
+++ b/Sprint-1/3-mandatory-interpret/2-time-format.js
@@ -12,14 +12,21 @@ console.log(result);
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+//[ChunYanWong] 6
 
 // b) How many function calls are there?
+//[ChunYanWong] 1
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// [ChunYanWong] the remainder - remaining seconds
+
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// [ChunYanWong] the movielength rounded to the neatest minutes
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// [ChunYanWong] the novie length in hours, minutes and seconds and resultHHMMSS may be better
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// [ChunYanWong] No, decimal number cannot be handled correctly
diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
index 60c9ace69a..3342792d7f 100644
--- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js
+++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
@@ -25,3 +25,8 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// [ChunYanWong] line 3 is used to remove the character "p" or the unit penny
+// [ChunYanWong] line 8 is used to add three 0 in front of the variable penceStringWithoutTrailingP
+// [ChunYanWong] line 9 is used to get the nearest pound from the variable above
+// [ChunYanWong] line 14 is used to get the remaining penny after converting to the nearest pound
+// [ChunYanWong] line 18 is used to display the result in pound and penny respectively
diff --git a/Sprint-1/4-stretch-explore/chrome.md b/Sprint-1/4-stretch-explore/chrome.md
index e7dd5feafe..0fa026a6a6 100644
--- a/Sprint-1/4-stretch-explore/chrome.md
+++ b/Sprint-1/4-stretch-explore/chrome.md
@@ -12,7 +12,14 @@ invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
 
+[ChunYanWong] Display an alert or message box in the browser with the message "Hello world!"
+
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
+
+[ChunYanWong] Display an input box to capture the user input
+
 What is the return value of `prompt`?
+
+[ChunYanWobg] Inputted name
diff --git a/Sprint-1/4-stretch-explore/objects.md b/Sprint-1/4-stretch-explore/objects.md
index 0216dee56a..7a970c82b1 100644
--- a/Sprint-1/4-stretch-explore/objects.md
+++ b/Sprint-1/4-stretch-explore/objects.md
@@ -6,11 +6,20 @@ Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
 
+[ChunYanWong] The syntax help for console.log
+
 Now enter just `console` in the Console, what output do you get back?
 
+[ChunYanWong] The syntax help for console
+
 Try also entering `typeof console`
 
 Answer the following questions:
 
 What does `console` store?
+
+[ChunYanWong] object
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+[ChunYanWong] The method of the object console or the functions of the object console