diff --git a/README.md b/README.md
index 2f9d18e..c3791e5 100644
--- a/README.md
+++ b/README.md
@@ -1,18 +1,28 @@
 # DART-HACKATHON-REPOSITORY
 
+
 # Dart Programs
 
 
 
 ## Program 1: Display Personal Information
-Write a Dart program using variables to display your name, age, school, and a hobby. Print it in one logical sentence.
+Wrote a Dart program using variables to display my name, age, school, and a hobby. Print it in one logical sentence.
 
 ## Program 2: Perform Mathematical Operations with Functions
-Write a Dart program that performs two mathematical operations using functions.
+- Was to write Dart program that performs two mathematical operations using functions.
+ - added some more math operations to enhance user experience
 
 ## Program 3: Determine Grade Based on Marks
-Write a Dart program to determine the grade based on a student's marks. The program should print out the appropriate grade according to the following criteria:
-- If the marks are greater than 85, print "Excellent".
-- If the marks are between 75 and 85 (inclusive), print "Very Good".
-- If the marks are between 65 and 75 (inclusive), print "Good".
-- If the marks are below 65, print "Average".
+Wrote a Dart program to determine the grade based on a student's marks. The program should print out the appropriate grade according to the following criteria:
+## I added the feature that the program should calcute the grade base on the average marks
+- If the average marks greater than 85, print "Excellent".
+- If the average marks between 75 and 85 (inclusive), print "Very Good".
+- If the average marks between 65 and 75 (inclusive), print "Good".
+- If the average marks are below 65, print "Average".
+
+## Feature
+- The program ask for user to input marks for 3 subjects
+- the average is auto calculated and the student is graded by the system
+
+### technology used
+- Dart
diff --git a/controlflow.dart b/controlflow.dart
index d6dc466..c61f409 100644
--- a/controlflow.dart
+++ b/controlflow.dart
@@ -1,7 +1,47 @@
+// Program 3: Determine Grade Based on Marks
+// Write a Dart program to determine the grade based on a student's marks. The program should print out the appropriate grade according to the following criteria:
+// - If the marks are greater than 85, print "Excellent".
+// - If the marks are between 75 and 85 (inclusive), print "Very Good".
+// - If the marks are between 65 and 75 (inclusive), print "Good".
+// - If the marks are below 65, print "Average".
+import 'dart:io';
+class studentGradingSystem{
 
-## Program 3: Determine Grade Based on Marks
-Write a Dart program to determine the grade based on a student's marks. The program should print out the appropriate grade according to the following criteria:
-- If the marks are greater than 85, print "Excellent".
-- If the marks are between 75 and 85 (inclusive), print "Very Good".
-- If the marks are between 65 and 75 (inclusive), print "Good".
-- If the marks are below 65, print "Average".
+  int english;
+  int maths ;
+  int science;
+  studentGradingSystem(this.english, this.maths, this.science);
+  String grade(){
+    int marks = (this.english + this.maths + this.science);
+    num Average = marks / 3;
+   
+    if(Average >= 85){
+      return "Excellent";
+    }
+    else if(Average >= 75 && maths >= 85){
+      return "Very Good";
+    }
+    else if(Average >= 65 && maths >= 75){
+      return "Good";
+    }
+    else if(Average < 65 && maths >= 65){
+      return "Average";
+    }
+    else{
+      return "Fail";
+    }
+  }
+}
+void main(){
+  print("********Welcome to the student grading system************");
+  print("Please enter your English language marks: ");
+  int english = int.parse(stdin.readLineSync()!);
+  print("Please enter your Maths marks: ");
+  int maths = int.parse(stdin.readLineSync()!);
+  print("Please enter your Science marks: ");
+  int science = int.parse(stdin.readLineSync()!);
+  studentGradingSystem student = studentGradingSystem(english, maths, science);
+String grade1 = student.grade();
+  print("Your grade is: $grade1");
+
+}
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diff --git a/functions.dart b/functions.dart
index 914640c..faad4a0 100644
--- a/functions.dart
+++ b/functions.dart
@@ -1,2 +1,54 @@
-## Program 2: Perform Mathematical Operations with Functions
-Write a Dart program that performs two mathematical operations using functions.
+// Program 2: Perform Mathematical Operations with Functions
+//Write a Dart program that performs two mathematical operations using functions.
+import 'dart:io';
+
+class MathematicsProgram{
+  int number1;
+  int number2;
+
+  MathematicsProgram(this.number1, this.number2);
+  int add(){
+    int result = number1 + number2;
+    return result;
+  }
+  int subtract(){
+    return number1 - number2;
+  }
+  int multiply(){
+    return number1 * number2;
+  }
+  num divide(){
+    return number1 / number2;
+  }
+}
+void main(){
+  //ask the user to enter two numbers
+  print("Enter the first number: ");
+
+  int num1 = int.parse(stdin.readLineSync()!);
+  print("Enter the second number: ");
+  int num2 = int.parse(stdin.readLineSync()!);
+
+  MathematicsProgram mp = MathematicsProgram(num1, num2);
+  print("Choose your operation: \n1. Add\n2. Subtract\n3. Multiply\n4. Divide\n");
+
+  int choice = int.parse(stdin.readLineSync()!);
+  switch(choice){
+    case 1:
+      print(mp.add());
+      break;
+    case 2:
+      print(mp.subtract());
+      break;
+    case 3:
+      print(mp.multiply());
+      break;
+    case 4:
+      print(mp.divide());
+      break;
+    default:
+      print("Invalid choice");
+      break;
+  }
+
+}
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diff --git a/program1..dart b/program1..dart
index d762a43..2a032e9 100644
--- a/program1..dart
+++ b/program1..dart
@@ -1,2 +1,8 @@
-## Program 1: Display Personal Information
-Write a Dart program using variables to display your name, age, school, and a hobby. Print it in one logical sentence.
+// Program 1: Display Personal Information
+void main(){
+  String name = "David";
+  int age = 22;
+  String school = 'Zetech University';
+  String hobby = 'Listening to music on Spotify';
+  print("My name is $name, I am $age years old, I live in $school and I like $hobby.");
+}
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