diff --git a/src/CircleArea.java b/src/CircleArea.java
new file mode 100644
index 0000000..ce21b6a
--- /dev/null
+++ b/src/CircleArea.java
@@ -0,0 +1,17 @@
+
+public class CircleArea implements ISubscriber{
+	
+	@Override
+	public void notifySubscriber(String input) {
+		double reduis=Double.parseDouble(input);
+		System.out.println("Area= "+area(reduis));
+		
+	}
+	
+
+	public double area(double reduis) {
+		double setArea=Math.PI * reduis *reduis;
+		return setArea;
+	}
+}
+
diff --git a/src/SphereArea.java b/src/SphereArea.java
new file mode 100644
index 0000000..e856d8d
--- /dev/null
+++ b/src/SphereArea.java
@@ -0,0 +1,25 @@
+import java.sql.SQLOutput;
+
+public class SphereArea implements ISubscriber {
+
+
+    @Override
+    public void notifySubscriber(String input) {
+
+        double R = Double.parseDouble(input);
+
+        double sphereArea = calcSphereArea(R);
+
+        System.out.println("The Sphere Area = " + sphereArea);
+
+    }
+
+    double calcSphereArea(double r){
+
+        double sphereArea = 0.0;
+
+        sphereArea = 4 * Math.PI * Math.pow(r, 2);
+
+        return sphereArea;
+    }
+}
diff --git a/src/SphereCircumference.java b/src/SphereCircumference.java
new file mode 100644
index 0000000..dac652c
--- /dev/null
+++ b/src/SphereCircumference.java
@@ -0,0 +1,24 @@
+public class SphereCircumference implements ISubscriber{
+	private double getSphereCircumference(double r) {
+		double area=2*Math.PI*r;
+		return area;
+	}
+	@Override
+	public void notifySubscriber(String input) {
+		double r;
+		try {
+			r=Double.parseDouble(input);
+		} catch (Exception e) {
+			System.out.println("enter a real number");
+			return;
+		}
+		
+		if(r<0) {
+			System.out.println("r must be >= 0");
+			return;
+		}
+		System.out.println("Area= "+getSphereCircumference(r));
+		
+	}
+
+}
diff --git a/src/Sphere_Volume.java b/src/Sphere_Volume.java
new file mode 100644
index 0000000..50315f6
--- /dev/null
+++ b/src/Sphere_Volume.java
@@ -0,0 +1,17 @@
+
+public class Sphere_Volume implements ISubscriber { 
+	@Override
+	public void notifySubscriber(String input) {
+		
+		double Radius = Double.parseDouble(input);
+		if(Radius < 0)
+		{
+			System.out.println("Radius can not be equal nagative number");
+		}
+		else {
+		double Volume = (4/3) * Math.PI * Math.pow(Radius, 3);
+		System.out.println("Volume = "+ Volume);
+		}
+		
+	}
+}
diff --git a/src/SummationSeries.java b/src/SummationSeries.java
new file mode 100644
index 0000000..3c84dc1
--- /dev/null
+++ b/src/SummationSeries.java
@@ -0,0 +1,15 @@
+public class SummationSeries implements ISubscriber
+{
+    @Override
+    public void notifySubscriber(String input)
+    {
+        int end = Integer.parseInt(input);
+        int sum = sigma(end);
+        System.out.println("The sum from 1 to the end number = " + sum);
+    }
+
+    public static int sigma(int end)
+    {
+        return (end*(end+1))/2;
+    }
+}
diff --git a/src/fibonacci.java b/src/fibonacci.java
new file mode 100644
index 0000000..ce2f362
--- /dev/null
+++ b/src/fibonacci.java
@@ -0,0 +1,22 @@
+public class fibonacci implements ISubscriber {
+	
+	int calcFib(String input){
+		int x = Integer.parseInt(input);
+		int ans = 0 ;
+		int fibN_1 = 1 ,fibN_2 = 1 ,fibN = 0;
+		
+		for(int i = 2 ; i < x ; i ++) {
+			fibN = fibN_1 + fibN_2;
+			fibN_2 = fibN_1;
+			fibN_1 = fibN;
+		}
+		return fibN;
+	}
+	@Override
+	 public void notifySubscriber(String input) {
+		// TODO Auto-generated method stub
+		
+		System.out.println("fibonacci of "+input+ " is " + calcFib(input));
+		
+	}
+}
\ No newline at end of file