diff --git a/Exercises/day_3/index.html b/Exercises/day_3/index.html
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index 0000000..4dc423c
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+++ b/Exercises/day_3/index.html
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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <script>
+        let [firstName, lastName, country, city, age, isMarried, year] = ["hoang", "tran", "viet nam", 22, true, 2022]
+        console.log(firstName, lastName, country, city, age, isMarried, year)
+        console.log(typeof(firstName), typeof(lastName), typeof(country), typeof(city), typeof(age), typeof(isMarried), typeof(year))
+
+        console.log("Check if type of '10' is equal to 10", '10' === "10")
+
+        console.log("Check if parseInt('9.8') is equal to 10:", parseInt('9.8') == 10)
+
+        console.log("Boolean value is either true or false:", typeof(true), typeof(false))
+
+        if(1){
+            if("1"){
+                if(true){
+                    console.log("truthy")
+                }
+            }
+        }
+
+        if(!0){
+            if(!NaN){
+                if(!undefined){
+                    if(!false){
+                        if(!""){
+                            if(!0n){
+                                console.log("falsy")
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+// 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' true
+// 4 === '4' false
+
+        console.log(`Find the length of python ${"python".length} and jargon ${"jargon".length} and make a falsy comparison statement: `, "python".length > "jargon".length)
+
+// 4 > 3 && 10 < 12 f
+// 4 > 3 && 10 > 12 f
+// 4 > 3 || 10 < 12 t
+// 4 > 3 || 10 > 12 t
+// !(4 > 3) f
+// !(4 < 3) t
+// !(false) t
+// !(4 > 3 && 10 < 12) t
+// !(4 > 3 && 10 > 12) t
+// !(4 === '4') t
+// There is no 'on' in both dragon and python
+        let now = new Date();
+
+        console.log("What is the year today?", now.getFullYear())
+        console.log("What is the month today as a number?", now.getMonth() + 1)
+        console.log("What is the date today?", now.getDate())
+        console.log("What is the day today as a number?", now.getDay())
+        console.log("What is the hours now?", now.getHours())
+        console.log("What is the minutes now?", now.getMinutes())
+        console.log("Find out the numbers of seconds elapsed from January 1, 1970 to now.", now.getTime())
+// 
+    </script>
+</body>
+</html>
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diff --git a/Exercises/day_3/index2.html b/Exercises/day_3/index2.html
new file mode 100644
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+++ b/Exercises/day_3/index2.html
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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <button id="tri-area">Calculate triangle area</button>
+    <button id="time-now">Display time</button>
+    <script>
+        let triArea = document.getElementById("tri-area")
+        triArea.onclick = function(){calTriangleArea()}
+        function calTriangleArea(){
+            let base = parseFloat(prompt("enter base of triangle"))
+            let height = parseFloat(prompt("enter height of triangle"))
+            let area = base*height*0.5
+            alert(`area of a triangle ${area}`)
+            console.log("calTriangleArea executed")
+            return area
+        }
+
+        let timeNow = document.getElementById("time-now")
+
+        function convertMiutesMiliseconds(time){
+            time < 10 ? time = `0${time}` : time
+            return time
+        }
+
+        timeNow.onclick = function(){displayTimeNow()}
+        function displayTimeNow(){
+            let now = new Date()
+            let readableTime = `This is ${now.getHours()}:${convertMiutesMiliseconds(now.getMinutes())}:${convertMiutesMiliseconds(now.getSeconds())}`
+            confirm(readableTime) 
+        }
+    </script>
+</body>
+</html>
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diff --git a/Exercises/day_4/index.html b/Exercises/day_4/index.html
new file mode 100644
index 0000000..aa75325
--- /dev/null
+++ b/Exercises/day_4/index.html
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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <button id="drive-condition">Calculate drive condition</button>
+    <button id="age-comparition">Compare age</button>
+    <button id="grades-calculate">Calculate grades</button>
+    <button id="season">Find season</button>
+    <script>
+
+    // Get user input using prompt(“Enter your age:”). If user is 18 or older , give feedback:'You are old enough to drive' but if not 18 give another feedback stating to wait for the number of years he needs to turn 18.
+
+    // Enter your age: 30
+    // You are old enough to drive.
+
+    // Enter your age:15
+    // You are left with 3 years to drive.
+    let btnCalDriveAge = document.getElementById("drive-condition");
+    btnCalDriveAge.onclick = function(){calDriveAge()}
+
+    function calDriveAge(){
+        let age = parseInt(prompt("Enter your age:"));
+        
+        if (age >= 18){
+            confirm(`You are left ${age} enough to drive`)
+        } else if (age >= 1){
+            confirm(`You are ${18 - age} years to drive`)
+        } else {
+            confirm("Please enter incorrect age")
+        }
+    }
+
+    // Compare the values of myAge and yourAge using if … else. Based on the comparison and log the result to console stating who is older (me or you). Use prompt(“Enter your age:”) to get the age as input.
+
+    // Enter your age: 30
+    // You are 5 years older than me.
+
+    let btnAgeCmp = document.getElementById("age-comparition");
+    btnAgeCmp.onclick = function(){cmpAge()}
+
+    function cmpAge(){
+        let now = new Date
+        let myAge = now.getFullYear() - 2000
+        let yourAge = parseInt(prompt("Enter your age"))
+        let subAge = yourAge - myAge
+
+        if (yourAge <= 0){
+            confirm("You need enter correct age")
+            return;
+        }
+
+        if (subAge < 0) {
+            confirm(`You are ${Math.abs(subAge)} younger than me`)
+        } else {
+            confirm(`You are ${Math.abs(subAge)} older than me`)
+        }
+    }
+
+    // Write a code which can give grades to students according to theirs scores:
+    // 80-100, A
+    // 70-89, B
+    // 60-69, C
+    // 50-59, D
+    // 0-49, F
+    let btnGradesCal = document.getElementById("grades-calculate");
+    btnGradesCal.onclick = function(){calGrades()}
+
+    function calGrades(){
+        let yourScore = parseInt(prompt("Enter your score"))
+
+        switch (true){
+            case (yourScore <= 100 && yourScore >= 80):
+                confirm("You are A")
+                break
+            case (yourScore < 90 && yourScore >= 70):
+                confirm("You are B")
+                break
+            case (yourScore < 70 && yourScore >= 60):
+                confirm("You are C")
+                break
+            case (yourScore < 60 && yourScore >= 50):
+                confirm("You are D")
+                break
+            case (yourScore < 50 && yourScore >= 0):
+                confirm("You are F")
+                break
+            default:
+                confirm("You need enter correct score")
+        }
+    }
+
+    // Check if the season is Autumn, Winter, Spring or Summer. If the user input is :
+    // September, October or November, the season is Autumn.
+    // December, January or February, the season is Winter.
+    // March, April or May, the season is Spring
+    // June, July or August, the season is Summer
+    let btnSeason = document.getElementById("season");
+    btnSeason.onclick = function(){findSeason()}
+
+    function findSeason(){
+        let autumn = ["September", "October", "November"]
+        let winter = ["December", "January", "February"]
+        let spring = ["March", "April", "May"]
+        let summer = ["June", "July", "August"]
+
+        let month = prompt("Enter month:(letter)")
+        month = month.toLowerCase().charAt(0).toUpperCase() + month.slice(1)
+        console.log(month)
+
+        switch (true){
+            case autumn.includes(month):
+                confirm("It's autumn")
+                break
+            case winter.includes(month):
+                confirm("It's winter")
+                break
+            case spring.includes(month):
+                confirm("It's spring")
+                break
+            case summer.includes(month):
+                confirm("It's summer")
+                break
+            default:
+                confirm("Please enter correct month")
+        }
+        
+    }
+    </script>
+</body>
+</html>
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