diff --git a/01_Day_Introduction/01_day_starter/datatypes.js b/01_Day_Introduction/01_day_starter/datatypes.js
new file mode 100644
index 0000000..fe5dbf3
--- /dev/null
+++ b/01_Day_Introduction/01_day_starter/datatypes.js
@@ -0,0 +1,6 @@
+// Use the typeof operator to check data types
+
+console.log(typeof name);
+console.log(typeof isStudent);
+console.log(typeof age);
+console.log(typeof favoriteColor);
diff --git a/01_Day_Introduction/01_day_starter/index.html b/01_Day_Introduction/01_day_starter/index.html
index 7ed5b19..c1cc0e5 100644
--- a/01_Day_Introduction/01_day_starter/index.html
+++ b/01_Day_Introduction/01_day_starter/index.html
@@ -13,6 +13,7 @@
 	<script src="./introduction.js"></script>
 	<script src="./variable.js"></script>
 	<script src="./main.js"></script>
+	<script src="datatypes.js"></script>
 
 </body>
 
diff --git a/01_Day_Introduction/01_day_starter/introduction.js b/01_Day_Introduction/01_day_starter/introduction.js
index 316199c..a3b02eb 100644
--- a/01_Day_Introduction/01_day_starter/introduction.js
+++ b/01_Day_Introduction/01_day_starter/introduction.js
@@ -1 +1,3 @@
-console.log('Welcome to 30DaysOfJavaScript')
\ No newline at end of file
+console.log('Welcome to 30DaysOfJavaScript')
+
+//comments can make code readable
\ No newline at end of file
diff --git a/01_Day_Introduction/01_day_starter/main.js b/01_Day_Introduction/01_day_starter/main.js
index 2b952bc..f1195ec 100644
--- a/01_Day_Introduction/01_day_starter/main.js
+++ b/01_Day_Introduction/01_day_starter/main.js
@@ -1,4 +1,11 @@
 // the variable values can be accessed from other variable.js file
+/*
 console.log(firstName, lastName, country, city, age, isMarried) 
 console.log(gravity, boilingPoint, PI) // 9.81, 100, 3.14
-console.log(name, job, live)
\ No newline at end of file
+console.log(name, job, live)
+*/
+//welcome to 30DaysofJavaScript
+
+/* comments can make code readable
+    easy to reuse and informative
+*/
\ No newline at end of file
diff --git a/01_Day_Introduction/01_day_starter/variable.js b/01_Day_Introduction/01_day_starter/variable.js
index 62558cb..bc6b3ff 100644
--- a/01_Day_Introduction/01_day_starter/variable.js
+++ b/01_Day_Introduction/01_day_starter/variable.js
@@ -1,20 +1,48 @@
-// Declaring different variables of different data types
+// Declare and assign string data type
+const name = 'Gideon';
 
-let firstName = 'Asabeneh'    // first name of a person
-let lastName = 'Yetayeh'      // last name of a person
-let country = 'Finland'       // country
-let city = 'Helsinki'         // capital city
-let age = 100                 // age in years
-let isMarried = true
+// Declare and assign boolean data type
+const isStudent = true;
 
-// Declaring variables with number values
+// Declare a variable without assignment (undefined)
+  //let age;
 
-const gravity = 9.81         // earth gravity  in m/s2
-const boilingPoint = 100     // water boiling point, temperature in oC
-const PI = 3.14              // geometrical constant
+// Declare and assign null data type
+const favoriteColor = null;
 
-// Variables can also be declaring in one line separated by comma
+// Declaring four variables without assigning values
+let gideon
+let asabeneh
+let gitHub
+let nike
 
-let name = 'Asabeneh',     //name of a person
-  job = 'teacher',
-  live = 'Finland'
+// Declaring four variables with assigned values
+let randomName = 'Eren';
+let year = 2023;
+let month = 'August';
+let favoriteFruit = 'apple';
+
+// Declaring variables in multiple lines
+ /* const firstName = 'Gideon';
+  const lastName = 'Buba';
+  let isMarried = True;
+  let country = 'Nigeria';
+  const age = 21; */
+
+// Declaring varibles in a signle line 
+let firstName = 'Gideon', lastName = 'Buba', isMarried = true, age = 21;
+
+//variables to log to browser console
+myAge = 21;
+yourAge = 30;
+
+console.log('I am', myAge , 'years old');
+console.log('I am', yourAge, 'years old');
+
+
+
+// Print the variables to the console
+console.log('Name:', name);
+console.log('Is Student:', isStudent);
+console.log('Age:', age);
+console.log('Favorite Color:', favoriteColor);
diff --git a/01_Day_Introduction/variable.js b/01_Day_Introduction/variable.js
index f5872af..8ca5187 100644
--- a/01_Day_Introduction/variable.js
+++ b/01_Day_Introduction/variable.js
@@ -15,3 +15,6 @@ const PI = 3.14 // geometrical constant
 let name = 'Asabeneh', //name of a person
   job = 'teacher',
   live = 'Finland'
+
+// Varibles of different data types from excercises
+ 
diff --git a/02_Day_Data_types/02_day_starter/main.js b/02_Day_Data_types/02_day_starter/main.js
index 7762908..b21a1a2 100644
--- a/02_Day_Data_types/02_day_starter/main.js
+++ b/02_Day_Data_types/02_day_starter/main.js
@@ -1 +1,185 @@
-// this is your main.js script
\ No newline at end of file
+// this is your main.js script
+
+//Excercises for Day 2
+//Exercise 1
+let challenge = '30 Days Of JavaScript';
+
+//Exercise 2
+console.log(challenge)
+
+//Exercise 3
+console.log(challenge.length)
+
+//Exercise 4
+console.log(challenge.toUpperCase())
+
+//Exercise 5
+console.log(challenge.toLocaleLowerCase())
+
+//Exercise 6
+console.log(challenge.substring(2, 8))
+
+//Exercise 7
+console.log(challenge.substring(0, 2))
+
+//Exercise 8
+console.log(challenge.includes('Script'))
+
+//Exercise 9
+console.log(challenge.split())
+
+//Exercise 10
+console.log(challenge.split(' '))
+
+//Exercise 11
+let companies = 'Facebook, Google, Microsoft, Apple, IBM, Oracle, Amazon'
+console.log(companies.split(','))
+
+//Exercise 12
+console.log(challenge.replace('JavaScript', 'Python'))
+
+//Exercise 13
+console.log(challenge.charAt(15))
+
+//Exercise 14
+console.log(challenge.charCodeAt(8))
+
+//Exercise 15
+console.log(challenge.indexOf('a'));
+
+//Exercise 16
+console.log(challenge.lastIndexOf('a'));
+
+//Exercise 17
+let sentence = 'You cannot end a sentence with because because because is a conjunction';
+console.log(sentence.indexOf('because'))
+
+//Exercise 18
+console.log(sentence.lastIndexOf('because'))
+
+//Exercise 19
+console.log(sentence.search('because'))
+
+//Exercise 20
+let whiteSpace = ' 30 days of JavaScript ';
+console.log(whiteSpace.trim())
+
+//Exercise 21
+console.log(challenge.startsWith('30'))
+
+//Exercise 22
+console.log(challenge.endsWith('JavaScript'))
+
+//Exercise 23
+console.log(challenge.match())
+
+//Exercise 24
+const firstString = '30 Days of ';
+const secondString = 'JavaScript';
+
+const mergedString = firstString.concat(secondString);
+
+console.log(mergedString); 
+
+//Exercise 25
+console.log(challenge.repeat(2))
+
+
+
+                        //Exercise Level 2
+//Exercise 1
+console.log(`The quote "There is no exercise better for the heart than reaching down and lifting people up." by John Holmes teaches us to help one another.`)
+
+//Exercise 2
+console.log("Love is not patronizing and charity isn't about pity, it is about love. Charity and love are the same -- with charity you give love, so don't just give money but reach out your hand instead.")
+
+//Exercise 3
+let strNumber = '10';
+console.log(parseInt(strNumber));
+
+//Exercise 4
+let float = '9.8';
+console.log(Math.ceil(float))
+
+//Exercise 5
+let word1 = 'Python'
+let word2 = 'Jargon'
+
+console.log(word1.includes('on'))
+console.log(word2.includes('on'))
+
+//Exercise 6
+let word = 'I hope this course is not full of jargon. Check if jargon is in the sentence.'
+
+console.log(word.includes('jargon'))
+
+//Exercise 7
+const num = Math.floor(Math.random() * 99);
+
+console.log(num);
+
+//Exercise 8
+const min = 50;
+const max = 100;
+const randomNumber = Math.floor(Math.random() * (max - min + 1)) + min;
+
+console.log(randomNumber);
+
+//Exercise 9
+const randNum = Math.floor(Math.random() * 254)
+
+console.log(randNum);
+
+//Exercise 10
+let string = 'JavaScript';
+
+let randomIndex = Math.floor((Math.random() * string.length))
+
+console.log(randomIndex)
+
+//Exercise 11
+
+
+//Exercise 12
+let subStr = 'You cannot end a sentence with because because because is a conjunction';
+const removedWord = subStr.slice(30, 54)
+
+console.log(removedWord)
+
+
+                        // Exercise Level 3
+
+// Exercise 1
+let numberOfWords = 'Love is the best thing in this world. Some found their love and some are still looking for their love.';
+
+console.log(numberOfWords.match(/love/gi))
+
+//Exercise 2
+let numWords = 'You cannot end a sentence with because because because is a conjunction'
+console.log(numWords.match(/because/gi))
+
+//Exercise 3
+const expression = "I am a teacher, and I love teaching. There is nothing as more rewarding as educating and empowering people. I found teaching more interesting than any other jobs. Does this motivate you to be a teacher? This 30 Days Of JavaScript is also the result of love of teaching.";
+
+//Exercise 4
+// Calculate the total annual income of the person by extracting the numbers from the following text. 'He earns 5000 euro from salary per month, 10000 euro annual bonus, 15000 euro online courses per month.' 
+
+const annualIncome = 'He earns 5000 euro from salary per month, 10000 euro annual bonus, 15000 euro online courses per month.' 
+
+const numberPattern = /\d+/g;
+
+console.log(numberPattern)
+
+const numbers = annualIncome.match(numberPattern);
+
+const monthlySalary = parseInt(numbers[0]);
+const annualBonus = parseInt(numbers[1]);
+const monthlyCoursesIncome = parseInt(numbers[2]);
+
+const totalAnnualIncome = (monthlySalary * 12) + annualBonus + (monthlyCoursesIncome * 12);
+
+console.log(`Total Annual Income: ${totalAnnualIncome} euro`);
+
+
+
+
diff --git a/03_Day_Booleans_operators_date/03_day_starter/scripts/main.js b/03_Day_Booleans_operators_date/03_day_starter/scripts/main.js
index 7762908..e0629d5 100644
--- a/03_Day_Booleans_operators_date/03_day_starter/scripts/main.js
+++ b/03_Day_Booleans_operators_date/03_day_starter/scripts/main.js
@@ -1 +1,213 @@
-// this is your main.js script
\ No newline at end of file
+// this is your main.js script
+                                            // Day 3 Exercises
+                                            // Exercise Level 1
+
+// Exercise 1
+ const firstName = 'Gideon';
+ const lastName = 'Buba';
+ let country = 'Nigeria'; 
+ const age = '23';
+ let isMarried = false;
+ let year = 2023;
+ 
+ console.log(typeof(firstName))
+ console.log(typeof(lastName))
+ console.log(typeof(country))
+ console.log(typeof(age))
+ console.log(typeof(isMarried))
+ console.log(typeof(year))
+
+ // Exercise 2
+let string = '10'
+let number = 10;
+
+console.log(string === number) //false
+
+// Exercise 3
+let decimal = 9.8;
+let wholeNumber = 10;
+
+console.log(parseInt(decimal) === wholeNumber);
+
+// Exercise 4
+    // Truthy value
+    'true'
+    'Hello World'
+    'Gideon'
+    // Falsy value
+    'false'
+    '0'
+    'null'
+
+// Exercsie 5
+//Choices without console.log()
+4 > 3                           //true
+4 >= 3                          //true
+4 < 3                           //false
+4 <= 3                          //false
+4 == 4                          //true
+4 === 4                         //true
+4 != 4                          //false
+4 !== 4                         //false
+4 != '4'                        //true
+4 == '4'                        //false
+4 === '4'                       //false
+
+//choices with console.log()
+console.log(4 > 3)              //true
+console.log(4 >= 3)             //true
+console.log(4 < 3)              //false
+console.log(4 <= 3)             //false
+console.log(4 == 4)             //true
+console.log(4 === 4)            //true
+console.log(4 != 4)             //false
+console.log(4 !== 4)            //false
+console.log(4 != '4')           //true
+console.log(4 == '4')           //true
+console.log(4 === '4')          //false
+
+let python = 'python';
+let jargon = 'jargon';
+
+let pythonLenght = python.length;
+let jargonLenght = jargon.length;
+
+console.log(pythonLenght === jargonLenght)
+
+// Exercise 6
+//choices without console.log
+4 > 3 && 10 < 12                //true 
+4 > 3 && 10 > 12                //false
+4 > 3 || 10 < 12                //true
+4 > 3 || 10 > 12                //true
+!(4 > 3)                        //false
+!(4 < 3)                        //true
+!(false)                        //true
+!(4 > 3 && 10 < 12)             //false
+!(4 > 3 && 10 > 12)             //true
+!(4 === '4')                    //true
+
+//choices with console.log()
+console.log(4 > 3 && 10 < 12)  
+//true        
+console.log(4 > 3 && 10 > 12)
+//false
+console.log(4 > 3 || 10 < 12)
+//true
+console.log(4 > 3 || 10 > 12)
+//true
+console.log(!(4 > 3))
+//false
+console.log(!(4 < 3))
+//true
+console.log(!(false))
+//true
+console.log(!(4 > 3 && 10 < 12))
+//false
+console.log(!(4 > 3 && 10 > 12))
+//true
+console.log(!(4 === '4'))
+//true
+
+// Exercise 7
+//todays year
+let date = new Date();
+console.log(date.getFullYear())         //'2021'
+
+//todays month
+console.log(date.getMonth())            //'8' (January is zero, so December has a value of one less than January.)
+
+//todays date
+console.log(date.getDate())             //'9'
+
+//todays day
+console.log(date.getDay())              //'5'
+
+//hour as of now
+console.log(date.getHours())            //'8'
+
+//minute as of now
+console.log(date.getMinutes())          //'6'
+
+//seconds from January 1, 1970 to now
+
+
+
+                                            // Exercise Level 2
+// Exercise 1                                            
+let base = prompt('Enter base of the triangle: ')
+let height = prompt('Enter height of the triangle: ')
+
+let area = 0.5 * base * height
+
+console.log(`The area of the triangle is ${area}: `)
+
+// Exercise 2
+let sideA = prompt('Enter side a:')
+let sideB = prompt('Enter side b:')
+let sideC = prompt('Enter side c:')
+
+let perimiter = sideA + sideB + sideC
+console.log(`The perimeter of a triangle is ${perimiter}`)
+
+//Exercise 3
+let length = prompt('Enter lenght:')
+let width = prompt('Enter Width:')
+
+let perimeterOfRectangle = 2 * (length * width)
+let areaOfRectangle = length * width * perimeterOfRectangle
+
+console.log(`The area of the rectangle is ${areaOfRectangle}`)
+
+// Exercise 4
+let radius  =  prompt('Enter radius of the circle:')
+let pi = Math.PI
+
+let areaOfCircle =  pi * radius * radius
+let circumference = 2 * pi * radius
+
+console.log(`The area of the circle is ${area}: `);
+console.log(`The circumfrence of the circle is ${circumference}: `);
+
+// Exercise 5 
+const slope = 2;
+const xIntercept = 1;
+const yIntercept = -2;
+
+console.log(`Slope: ${slope}`);
+console.log(`X-Intercept: ${xIntercept}`);
+console.log(`Y-Intercept: ${yIntercept}`);
+
+// Exercise 6
+const x1 = 2;
+const y1 = 2;
+const x2 = 6;
+const y2 = 10;
+
+const slope2 = (y2 - y1) / (x2 - x1);
+
+console.log("The slope between the points is:", slope);
+
+// Exercise 7
+
+// Exercise 8
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+