diff --git a/Sprint-1/1-key-exercises/1-count.js b/Sprint-1/1-key-exercises/1-count.js
index 117bcb2b6..2711fd150 100644
--- a/Sprint-1/1-key-exercises/1-count.js
+++ b/Sprint-1/1-key-exercises/1-count.js
@@ -1,6 +1,9 @@
 let count = 0;
 
 count = count + 1;
+/* in line three, the variable count is reassign new value by increment it current value by 1.
+*/
+console.log(count);
 
 // 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
diff --git a/Sprint-1/1-key-exercises/2-initials.js b/Sprint-1/1-key-exercises/2-initials.js
index 47561f617..10cc52f0a 100644
--- a/Sprint-1/1-key-exercises/2-initials.js
+++ b/Sprint-1/1-key-exercises/2-initials.js
@@ -5,7 +5,8 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = firstName.charAt(0)+middleName.charAt(0)+lastName.charAt(0);
+console.log(initials);
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
diff --git a/Sprint-1/1-key-exercises/3-paths.js b/Sprint-1/1-key-exercises/3-paths.js
index ab90ebb28..4c6b41eed 100644
--- a/Sprint-1/1-key-exercises/3-paths.js
+++ b/Sprint-1/1-key-exercises/3-paths.js
@@ -16,8 +16,17 @@ 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 slashIndex = filePath.indexOf("/");
+const dir =filePath.slice(slashIndex + 0, 45) ;
+const ext =filePath.slice(slashIndex + 49, 53);
+console.log(`The dir part of ${filePath} is ${dir}`);
+console.log(`The ext part of ${filePath} is ${ext}`);
+*/
+ 
+let dirDirectory = filePath.slice(filePath.indexOf("/"),filePath.lastIndexOf("/"));
+let extDirectory = filePath.slice(filePath.lastIndexOf("/"));
+console.log(`The dir part of the file is ${dirDirectory}.`);
+console.log(`The ext part of the file is ${extDirectory}.`);
 
 // https://www.google.com/search?q=slice+mdn
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diff --git a/Sprint-1/1-key-exercises/4-random.js b/Sprint-1/1-key-exercises/4-random.js
index 292f83aab..5133cbed3 100644
--- a/Sprint-1/1-key-exercises/4-random.js
+++ b/Sprint-1/1-key-exercises/4-random.js
@@ -3,7 +3,16 @@ const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
+console.log(num)
+
 // In this exercise, you will need to work out what num represents?
 // 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
+
+/*Number data type represents any type of number such as integer, float number(decimal number), infinity number, etc...
+In the code at line 4 the num variable are doing math function that generate a integer between variable minimum and maximum value,
+the floor method behind the Math are is main purpose if to help turn value of a float number and round it up to the nearest integer.
+inside the Math.floor parameter the math random method is choosing a random float number between 0 and 1 and have it multiply with the second expression
+to set the range of possible value range from 0 to under 100. The last plus one to make sure the that number stay above 0(0+1) and to 100(99+1);
+*/
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diff --git a/Sprint-1/2-mandatory-errors/0.js b/Sprint-1/2-mandatory-errors/0.js
index cf6c5039f..eb485e19f 100644
--- a/Sprint-1/2-mandatory-errors/0.js
+++ b/Sprint-1/2-mandatory-errors/0.js
@@ -1,2 +1,4 @@
-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?
+By comment both the line 1 and 2 out and the system should ignore these 2 line and see them as comment.
+*/
\ No newline at end of file
diff --git a/Sprint-1/2-mandatory-errors/1.js b/Sprint-1/2-mandatory-errors/1.js
index 7a43cbea7..3c88f39b3 100644
--- a/Sprint-1/2-mandatory-errors/1.js
+++ b/Sprint-1/2-mandatory-errors/1.js
@@ -1,4 +1,8 @@
 // trying to create an age variable and then reassign the value by 1
 
-const age = 33;
-age = age + 1;
+let age = 33;
+age += 1 ;
+
+console.log(age);
+
+/*By changing the variable from const to let since const variable value can't be change. I used prefix to increase the value and reassign it right away.*/
\ No newline at end of file
diff --git a/Sprint-1/2-mandatory-errors/2.js b/Sprint-1/2-mandatory-errors/2.js
index e09b89831..45eda0213 100644
--- a/Sprint-1/2-mandatory-errors/2.js
+++ b/Sprint-1/2-mandatory-errors/2.js
@@ -3,3 +3,7 @@
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+
+/*the main the error here is that the console.log try to print the expression string template with the variable cityOfBirth. But since in the variable
+cityOfBirth declare after the console.log, so the console.log when try to involve the cityOfBirth will return error since the it doesn't exist.
+*/
diff --git a/Sprint-1/2-mandatory-errors/3.js b/Sprint-1/2-mandatory-errors/3.js
index ec101884d..3872d807a 100644
--- a/Sprint-1/2-mandatory-errors/3.js
+++ b/Sprint-1/2-mandatory-errors/3.js
@@ -1,5 +1,7 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().slice(-4);
+console.log(last4Digits);
+console.log(typeof last4Digits);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
diff --git a/Sprint-1/2-mandatory-errors/4.js b/Sprint-1/2-mandatory-errors/4.js
index 21dad8c5d..0a22b02ff 100644
--- a/Sprint-1/2-mandatory-errors/4.js
+++ b/Sprint-1/2-mandatory-errors/4.js
@@ -1,2 +1,6 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
\ No newline at end of file
+const twelveHourClockTime = "20:53";
+const twentyFourHourClockTime = "08:53";
+console.log($12HourClockTime);
+console.log($24HourClockTime);
+
+/*For this error I I fix by changing the number 12 and 24 to word variable name because in JS number can't be used to begin writing a variable name */
\ No newline at end of file
diff --git a/Sprint-1/3-mandatory-interpret/1-percentage-change.js b/Sprint-1/3-mandatory-interpret/1-percentage-change.js
index e24ecb8e1..76c80706b 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;
@@ -20,3 +20,30 @@ console.log(`The percentage change is ${percentageChange}`);
 // d) Identify all the lines that are variable declarations
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+
+/*
+Answer
+a) In this section of the code, we have function calls  appear 5 time through out the code. Here is each of them on the line of code that
+they are call:
+  - Number(carPrice.replaceAll(",","")); in line  4 is a function calls because the .replaceALL is being executed
+  - Number(priceAfterOneYear.replaceAll(",", "")); in line 5 is also a function call because .replaceAll is being executed.
+  - Inside the Number() function the .replaceAll in both line 4 and 5 is also a function call because the the parent function is also
+   being executed.
+  - the console.log is a function calls
+So the total amount of function call in this code is 5
+
+b) The main error for the when the running this line of code if for the missing right parameter between the arguments, so fix this 
+just add the coma right after the double quote.
+
+c) There are 2 reassign variable statement at line 4 and line 5.
+
+d)There are 4 total variable declarations in this code:
+ - let carPrice = "10,00"; line 1
+ - let priceAfterOneYear ="8,543"; line 2
+ - const priceDifference = carPrice - priceAfterOneYear; line 7
+ - const percentageChange = (priceDifference / carPrice) * 100; line 8
+
+e) The expression Number(carPrice.replaceAll(",","")) are doing 2 main purpose, 
+ - The first purpose is to remove the coma from the string number "10000" and "8543".
+ - Is the changing the string number to number data type.
+*/
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diff --git a/Sprint-1/3-mandatory-interpret/2-time-format.js b/Sprint-1/3-mandatory-interpret/2-time-format.js
index 47d239558..d0c275d6f 100644
--- a/Sprint-1/3-mandatory-interpret/2-time-format.js
+++ b/Sprint-1/3-mandatory-interpret/2-time-format.js
@@ -23,3 +23,31 @@ console.log(result);
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+
+/*
+Answer
+a)In this program there are 5 variable declarations:
+  -const movieLength = 8784; at line 1.
+  -const remainingSeconds = movieLength % 60; at line 3.
+  -const totalMinutes = (movieLength - remainingSeconds) / 60; at line 4.
+  -const remainingMinutes = totalMinutes % 60; at line 6.
+  -const totalHours = (totalMinutes - remainingMinutes) / 60; at line 7.
+
+b) There are only 1 function call in this program.
+  - console.log(result); at line 10
+
+c)At the line 3 we can see the the expression movieLength % 60, 
+what is represent is the reminder value after the division movieLength(in second) value by 60%; 
+this is to remind how much left over second left in the movie.
+
+d)In line 4, the the expression that is assigned to totalMinutes 
+represent the value after the math operation if movieLength value and remainingSeconds then divine by 60;
+
+e)For the variable result it represent the combine total time length of the movie in hour/minutes/second template, for better name for this variable
+I would to rename it to formattedMovieDuration.
+
+f) After the experimenting with different values of movieLength. As Long as the value in movieLength is a positive integer of second. It will 
+correctly produce the correct value in hours/minutes/second format. However for to the other value such as float number, string, negative integer
+and non numeric value. They might still print out in the format hours/minutes/second but some type will break code such as if string not a number or coma in a string
+number, negative value that don't reflect what this code try to do or decimal number that give incorrect result.
+*/
\ No newline at end of file
diff --git a/Sprint-1/3-mandatory-interpret/3-to-pounds.js b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
index 60c9ace69..fbf4af92b 100644
--- a/Sprint-1/3-mandatory-interpret/3-to-pounds.js
+++ b/Sprint-1/3-mandatory-interpret/3-to-pounds.js
@@ -24,4 +24,31 @@ console.log(`£${pounds}.${pence}`);
 // Try and describe the purpose / rationale behind each step
 
 // To begin, we can start with
-// 1. const penceString = "399p": initialises a string variable with the value "399p"
+/* 
+1. const penceString = "399p": initializes a string variable with the value "399p".
+
+2. const penceStringWithoutTrailingP: this variable is now store a new value of penceString "399".
+By using the .substring method(.slice method predecessor)it remove the p from the penceString value and 
+reassign the new value to variable penceStringWithoutTrailingP. It start from index position 0 in this case "3" and stop at the index 2 "9".
+
+3. const paddedPenceNumberString: this variable main role is to check if the string value total length 
+at least 3, if the length short then padStart will add 0 the left from the first index(0) in this case "3" until the string length total is 3. In this case 
+it select the string number "3".
+
+4. const pounds: this variable is role is to extract the pound value from the paddedPenceNumberString.
+Inside the the paddedPenceNumberString subString method parameter it have 2 value 0 and paddedPenceNumberString total string length minus 1,
+the 0 is the index of the  string number that we would like to start while .length - 2 is to tell the SubString method where to stop in this case the  first "9".
+
+5) const pence: as the name suggest this variable main role is to extract he pence value from the paddedPenceNumberString variable.
+How ever this variable there are 2 method is used.
+ -subString method is used to slice the string value "99" off the "399" value, how ever is now only have 1 value
+ is the length of the "399" is 3 now - 2 equal to 1 and no end value. The main reason is to select where the slice will begin stop at the end 
+ of the string.
+ -padEnd method work exactly the same as padStart but in reverse. The padEnd method is checking to see is the paddedPenceNumberString string length at least total of 2, 
+ if not they will add 0 from the selected index position from the string value "99" from the index 0 in this case is "9" to the right.
+
+6)console.log(`£${pounds}.${pence}`): is to log and print out the value inside the terminal by using the string template, the back tick is to 
+define a template literal. Then inside the template the pound sign(£) is show the pound currency, the money sign before the curly bracket is to allow 
+embed variables in this case pounds and pence that separate by dot that print out a float string value.
+*/
+ 
\ No newline at end of file