diff --git a/Gradebook/Gradebook.csproj b/Gradebook/Gradebook.csproj
new file mode 100644
index 00000000..23df6047
--- /dev/null
+++ b/Gradebook/Gradebook.csproj
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp2.1</TargetFramework>
+  </PropertyGroup>
+
+</Project>
diff --git a/Gradebook/Program.cs b/Gradebook/Program.cs
new file mode 100644
index 00000000..8f5842bb
--- /dev/null
+++ b/Gradebook/Program.cs
@@ -0,0 +1,158 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace GradeBook
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            //declare main variable
+            Dictionary<String, String> gradeBook = new Dictionary<String, String>();
+            Dictionary<String, int> gradeBookMax = new Dictionary<String, int>();
+            Dictionary<String, int> gradeBookMin = new Dictionary<String, int>();
+            Dictionary<String, decimal> gradeBookAvg = new Dictionary<String, decimal>();
+            String yesNo = " ";
+            //intro gradebook
+            Console.WriteLine("Gradebook:");
+            //this does the collecting of the data and interacting with user
+            //try-catch for data entry errors
+            try
+            {
+                dataEntry(gradeBook, yesNo);
+            }
+            catch (Exception)
+            {
+                if (yesNo != "Y" || yesNo != "N")
+                {
+                    Console.WriteLine("");
+                    dataEntry(gradeBook, yesNo);
+                }
+            }
+            finally
+            {
+                Console.WriteLine("STUDENTS:");
+                foreach (KeyValuePair<String, String> student in gradeBook)
+                {
+                    Console.WriteLine($" Students: {student.Key} | Grades: {student.Value} ");
+                }
+                Console.WriteLine($"----------------------------------------------------");
+            }
+
+            maxGrade(gradeBook, gradeBookMax);
+            Console.WriteLine("MAX GRADES:");
+            foreach (KeyValuePair<String, int> student1 in gradeBookMax)
+            {
+                Console.WriteLine($" Students: {student1.Key} | Max Grade: {student1.Value} ");
+            }
+            Console.WriteLine("---------------------------------------------------------");
+
+            minGrade(gradeBook, gradeBookMin);
+            Console.WriteLine("MIN GRADES:");
+            foreach (KeyValuePair<String, int> student2 in gradeBookMin)
+            {
+                Console.WriteLine($" Students: {student2.Key} | Min Grade: {student2.Value} ");
+            }
+            Console.WriteLine("----------------------------------------------------------");
+
+            avgGrade(gradeBook, gradeBookAvg);
+            Console.WriteLine("AVERAGE GRADES:");
+            foreach (KeyValuePair<String, decimal> student3 in gradeBookAvg)
+            {
+                Console.WriteLine($" Students: {student3.Key} | Min Grade: {student3.Value} ");
+            }
+            Console.WriteLine("-----------------------------------------------------------");
+        }
+
+        public static Dictionary<String, String> dataEntry(Dictionary<String, String> gradeBook, String yesNo)
+        {
+            //declare variables
+            String studentName = " "; //key
+            String studentGrades = " "; //value
+
+            //while conditionals are true the app continues to get data
+            while (true)
+        
+                //if the user does not enter yes or no, they try again.
+                Console.WriteLine("Select Y to enter data, N to return calculations.");
+                yesNo = Console.ReadLine().ToLower();
+                if (yesNo == "y" || yesNo == "yes")
+                {
+                    Console.WriteLine("Enter students name in format 'last name , first name'.");
+                    studentName = (Console.ReadLine().ToLower());
+
+                    Console.WriteLine($"Enter grades for {studentName}.\nEach grade must be seperated by a comma.\nExample: (88,95)");
+                    studentGrades = Console.ReadLine();
+
+                    gradeBook.Add(studentName, studentGrades);
+                }
+                else if (yesNo == "n" || yesNo == "no")
+                {
+                    break;
+
+                }
+                else
+                {
+                    throw new Exception("Yes or No answers only.");
+                }
+            }
+            return gradeBook;
+        }
+        public static Dictionary<String, int> maxGrade(Dictionary<String, String> gradeBook, Dictionary<String, int> gradeBookMax)
+        {
+            foreach (KeyValuePair<String, String> student in gradeBook)
+            {
+                var studentMax = student.Key;
+                string[] splitMax = student.Value.Split(',');
+                //assumes 1st entry could be largest
+                int max1 = Convert.ToInt32(splitMax[0]);
+                //compares all entries in string []
+                foreach (var maxCheck in splitMax)
+                {
+                    int splitMaxGrade = Convert.ToInt32(maxCheck);
+                    if (splitMaxGrade > max1)
+                    {
+                        max1 = splitMaxGrade;
+                    }
+                }
+                gradeBookMax.Add(studentMax, max1);
+            }
+            return gradeBookMax;
+        }
+        public static Dictionary<String, int> minGrade(Dictionary<String, String> gradeBook, Dictionary<String, int> gradeBookMin)
+        {
+            foreach (KeyValuePair<String, String> student in gradeBook)
+            {
+                var studentMin = student.Key;
+                string[] splitMin = student.Value.Split(',');
+
+                int min1 = Convert.ToInt32(splitMin[0]);
+
+                foreach (var minCheck in splitMin)
+                {
+                    int splitMinGrade = Convert.ToInt32(minCheck);
+                    if (splitMinGrade < min1)
+                    {
+                        min1 = splitMinGrade;
+                    }
+                }
+                gradeBookMin.Add(studentMin, min1);
+            }
+            return gradeBookMin;
+        }
+        public static Dictionary<String, decimal> avgGrade(Dictionary<String, String> gradeBook, Dictionary<String, decimal> gradeBookAvg)
+        {
+            foreach (KeyValuePair<String, String> student in gradeBook)
+            {
+                var studentWAvg = student.Key;
+                String[] studentAvgSplit = student.Value.Split(',');
+                decimal[] studentAvg = studentAvgSplit.Select(x => Convert.ToDecimal(x)).ToArray();
+                decimal avg1 = studentAvg.Average();
+                gradeBookAvg.Add(studentWAvg, avg1);
+            }
+            return gradeBookAvg;
+        }
+    }
+}
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