diff --git a/Src/BootCamp.Chapter/Checks.cs b/Src/BootCamp.Chapter/Checks.cs
index 49864932a..4ce0cf783 100644
--- a/Src/BootCamp.Chapter/Checks.cs
+++ b/Src/BootCamp.Chapter/Checks.cs
@@ -17,25 +17,29 @@ public static class Checks
         public static int PromptInt(string message)
         {
             // To do: call your implementation. 
-            return 0;
+            var i = Lesson4.getThenConvertInt(message);
+            return i;
         }
 
         public static string PromptString(string message)
         {
             // To do: call your implementation. 
-            return "";
+            var i = Lesson4.getString(message);
+            return i;
         }
 
         public static float PromptFloat(string message)
         {
             // To do: call your implementation. 
-            return 0;
+            var i = Lesson4.getStringConvertFloat(message);
+            return i;
         }
 
         public static float CalculateBmi(float weight, float height)
         {
             // To do: call your implementation. 
-            return 0;
+            var i = Lesson4.calcBMI(weight, height);
+            return i;
         }
     }
 }
diff --git a/Src/BootCamp.Chapter/Lesson4.cs b/Src/BootCamp.Chapter/Lesson4.cs
new file mode 100644
index 000000000..e919ad453
--- /dev/null
+++ b/Src/BootCamp.Chapter/Lesson4.cs
@@ -0,0 +1,70 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+
+namespace BootCamp.Chapter
+{
+    internal class Lesson4
+    {
+            public static int getThenConvertInt(string message)
+            {
+            Console.WriteLine(message);
+            var input = Console.ReadLine();
+            int n;
+            bool isNumber = int.TryParse(input, out _);
+            if (!isNumber)
+            {
+                Console.WriteLine("\"" + input + "\"" + " is not a valid number.");
+                return -1;
+            }
+
+            return int.Parse(input);
+            }
+
+            public static string getString(string message)
+            {
+                Console.WriteLine(message);
+                var input = Console.ReadLine();
+            if (String.IsNullOrEmpty(input))
+            {
+                Console.WriteLine($"{message} Name cannot be empty {input}");
+                return "-";
+            }
+            return input;
+
+            }
+
+            public static float getStringConvertFloat(string message)
+            {
+                Console.WriteLine(message);
+                var input = Console.ReadLine();
+                bool isNumber = float.TryParse(input, out _);
+                if (isNumber) {
+                    return float.Parse(input);
+                }
+                else
+                {
+                    Console.WriteLine("\"" + input + "\"" + " is not a valid number.");
+                    return -1;
+
+                }
+            }
+
+            public static float calcBMI(float weight, float height)
+            {
+
+            if (weight <= 0 || height <= 0)
+            {
+                var reasons = "Failed calculating BMI. Reason:";
+                if (weight <= 0) reasons += $"/nWeight cannot be equal or less than zero, but was {weight} ";
+                if (height <= 0) reasons += $"/nHeight cannot be equal or less than zero, but was {height}" ;
+                Console.WriteLine(reasons);
+                return -1;
+            }
+                float BMI = ((float)(weight / (Math.Pow(height, 2))));
+                return BMI;
+            }
+        }
+    }
+
diff --git a/Src/BootCamp.Chapter/Program.cs b/Src/BootCamp.Chapter/Program.cs
index 94e5531bc..5581e8846 100644
--- a/Src/BootCamp.Chapter/Program.cs
+++ b/Src/BootCamp.Chapter/Program.cs
@@ -9,6 +9,41 @@ class Program
     {
         static void Main(string[] args)
         {
+            var weight = Lesson4.getThenConvertInt("Enter Weight");
+            var height = Lesson4.getThenConvertInt("Enter Height");
+            var name = Lesson4.getString("Enter Name");
+
+            var BMI = Lesson4.calcBMI(weight, height);
+
+
+
+            //Console.WriteLine("Please enter an First Name: ");
+            //var firstName = Console.ReadLine();
+            //Console.WriteLine($"Please enter {firstName}'s Last Name: ");
+            //var lastName = Console.ReadLine();
+            //var fullName = firstName + " " + lastName;
+            //Console.WriteLine($"Please enter {fullName}'s age: ");
+            //var age = Console.ReadLine();
+            //Console.WriteLine($"Please enter {fullName}'s Weight (kg): ");
+            //double weight = Convert.ToDouble(Console.ReadLine());
+            //Console.WriteLine($"Please enter {fullName}'s Height (cm): ");
+            //double height = Convert.ToDouble(Console.ReadLine());
+            Console.WriteLine($"{name}'s ,weight is {weight} height is {height} cm BMI is {BMI}");
+
+            //Console.WriteLine($"{fullName}'s BMI is {BMI.GetBMI((height / 100), weight)}");
+        }
+
+
+
+        // BMIformula = weight (lb) / [height (in)]2 x 703
+        public class BMI
+        {
+            public static double GetBMI(double height, double weight)
+            {
+                return (weight / (Math.Pow(height, 2)));
+            }
         }
+
+
     }
-}
+}
\ No newline at end of file
diff --git a/Src/Lesson3.cs b/Src/Lesson3.cs
new file mode 100644
index 000000000..285d204ac
--- /dev/null
+++ b/Src/Lesson3.cs
@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace BootCamp.Chapter
+{
+    internal class Lesson3
+    {
+            public static int getThenConvertInt(string message)
+            {
+            Console.WriteLine(message);
+            var input = Console.ReadLine();
+                return int.Parse(input);
+            }
+
+            public static string getString(string message)
+            {
+                Console.WriteLine(message);
+                var input = Console.ReadLine();
+                return input;
+
+            }
+
+            public static float getStringConvertFloat(string message)
+            {
+            Console.WriteLine(message);
+            var input = Console.ReadLine();
+                return float.Parse(input);
+            }
+
+            public static float calcBMI(float weight, float height)
+            {
+                float BMI = ((float)(weight / (Math.Pow(height, 2))));
+                return BMI;
+            }
+        }
+    }
+