diff --git a/README.md b/README.md
index 2f9d18e..f5f29ee 100644
--- a/README.md
+++ b/README.md
@@ -2,17 +2,21 @@
 
 # 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.
 
 ## Program 2: Perform Mathematical Operations with Functions
+
 Write a Dart program that performs two mathematical operations using functions.
 
 ## 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".
+
+All the best.
diff --git a/controlflow.dart b/controlflow.dart
index d6dc466..2b011dd 100644
--- a/controlflow.dart
+++ b/controlflow.dart
@@ -1,7 +1,35 @@
+// ## 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".
 
-## 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';
+
+void main() {
+  //prompt the user to enter an input
+  print("\nEnter your marks: \n");
+  int? marks = int.parse(stdin.readLineSync()!);
+  print("\nYour scrore is: ${marks}");
+
+  /*
+  check marks between 1 and 100
+  and print error message for marks 
+  outside this range
+  */
+  if (marks > 0 && marks <= 100) {
+    //check the grade
+    if (marks > 85) {
+      print("\nExcellent \n");
+    } else if (marks > 75) {
+      print("\nVery Good \n");
+    } else if (marks > 65) {
+      print("\nGood \n");
+    } else {
+      print("\nAverage \n");
+    }
+  } else {
+    print("\nERROR: Marks cannot be less than 1 or greater than 100. \n");
+  }
+}
diff --git a/functions.dart b/functions.dart
index 914640c..1c302f3 100644
--- a/functions.dart
+++ b/functions.dart
@@ -1,2 +1,32 @@
-## 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';
+
+void main() {
+  //prompt user to enter the fist number
+  print("\Enter the 1st number: \n");
+  int? any1stNumber = int.parse(stdin.readLineSync()!);
+
+  //prompt user to enter the second number
+  print("\Enter the 2nd number: \n");
+  int? any2ndNumber = int.parse(stdin.readLineSync()!);
+
+  //call the functions that implement the sum and the product
+  int sum = addTwoNums(any1stNumber, any2ndNumber);
+  int product = multiplyTwoNums(any1stNumber, any2ndNumber);
+
+  //Print the numbers entered
+  print("\nYou have entered ${any1stNumber} and ${any2ndNumber}");
+
+  //print the SUM and the product of the two numbers
+  print("\nThe sum of ${any1stNumber} and ${any2ndNumber} is ${sum} ");
+  print("\nThe product of ${any1stNumber} and ${any2ndNumber} is ${product}\n");
+}
+
+int addTwoNums(num1, num2) {
+  return (num1 + num2);
+}
+
+int multiplyTwoNums(num1, num2) {
+  return (num1 * num2);
+}
diff --git a/program1.dart b/program1.dart
new file mode 100644
index 0000000..eb90998
--- /dev/null
+++ b/program1.dart
@@ -0,0 +1,13 @@
+// ## 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.
+
+void main() {
+  String name = "Kipkorir";
+  num age = 50;
+  String school = "PLP";
+  String hobby = "Coding";
+
+  print(
+      "\nMy name is ${name}, aged ${age}, studying at ${school}. My hobby is ${hobby}.\n");
+}