diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 64db9d16..9d1a9477 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,4 +1,4 @@
-name: 'Run App <last name>, <first name>'
+name: 'Run App Hailu, Yohannes'
 
 on: [push, pull_request]
 
@@ -6,4 +6,12 @@ jobs:
   build-and-test:
     runs-on: ubuntu-latest
     steps:
-      - run: echo "Hello, World!"
+      - uses: actions/checkout@v2
+      - name: install dotnet
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '8.x'
+      - name: build
+        run: dotnet build
+      - name: run unit tests
+        run: dotnet test
\ No newline at end of file
diff --git a/Console/Program.cs b/Console/Program.cs
index 56bb8606..e443b5c8 100644
--- a/Console/Program.cs
+++ b/Console/Program.cs
@@ -86,6 +86,6 @@ public static double Divide(string x, string y)
 	// Implement this method following a similar pattern as above
 	public static double Power(string x, string y)
 	{
-		return 0.0;
-	}
+        return Math.Pow(double.Parse(x), double.Parse(y));
+    }
 }
diff --git a/Tests/UnitTests.cs b/Tests/UnitTests.cs
index a2d3bd18..7a27202e 100644
--- a/Tests/UnitTests.cs
+++ b/Tests/UnitTests.cs
@@ -3,27 +3,139 @@ namespace GithubActionsLab;
 [TestClass]
 public class Addition
 {
-	[TestMethod]
-	public void Add_Valid_Patino()
-	{
-		Assert.AreEqual(3, Program.Add("1", "2"));
-		Assert.AreEqual(5, Program.Add("3", "2"));
-		Assert.AreEqual(12, Program.Add("5", "7"));
-	}
-
-	[TestMethod]
-	public void Add_Invalid_Patino()
-	{
-		Assert.ThrowsException<FormatException>(() => Program.Add("1", "a"));
-		Assert.ThrowsException<FormatException>(() => Program.Add("a", "1"));
-		Assert.ThrowsException<FormatException>(() => Program.Add("a", "a"));
-	}
-
-	[TestMethod]
-	public void Add_Null_Patino()
-	{
-		Assert.ThrowsException<ArgumentNullException>(() => Program.Add("1", null));
-		Assert.ThrowsException<ArgumentNullException>(() => Program.Add(null, "1"));
-		Assert.ThrowsException<ArgumentNullException>(() => Program.Add(null, null));
-	}
+    [TestMethod]
+    public void Add_Valid_Hailu()
+    {
+        Assert.AreEqual(3, Program.Add("1", "2"));
+        Assert.AreEqual(5, Program.Add("3", "2"));
+        Assert.AreEqual(12, Program.Add("5", "7"));
+    }
+
+    [TestMethod]
+    public void Add_Invalid_Hailu()
+    {
+        Assert.ThrowsException<FormatException>(() => Program.Add("1", "a"));
+        Assert.ThrowsException<FormatException>(() => Program.Add("a", "1"));
+        Assert.ThrowsException<FormatException>(() => Program.Add("a", "a"));
+    }
+
+    [TestMethod]
+    public void Add_Null_Hailu()
+    {
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Add("1", null));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Add(null, "1"));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Add(null, null));
+    }
 }
+
+[TestClass]
+public class Subtraction
+{
+    [TestMethod]
+    public void Subtract_Valid_Hailu()
+    {
+        Assert.AreEqual(2, Program.Subtract("5", "3"));
+        Assert.AreEqual(0, Program.Subtract("2", "2"));
+        Assert.AreEqual(-4, Program.Subtract("3", "7"));
+    }
+
+    [TestMethod]
+    public void Subtract_Invalid_Hailu()
+    {
+        Assert.ThrowsException<FormatException>(() => Program.Subtract("1", "a"));
+        Assert.ThrowsException<FormatException>(() => Program.Subtract("a", "1"));
+        Assert.ThrowsException<FormatException>(() => Program.Subtract("a", "a"));
+    }
+
+    [TestMethod]
+    public void Subtract_Null_Hailu()
+    {
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Subtract("1", null));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Subtract(null, "1"));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Subtract(null, null));
+    }
+}
+
+[TestClass]
+public class Multiplication
+{
+    [TestMethod]
+    public void Multiply_Valid_Hailu()
+    {
+        Assert.AreEqual(6, Program.Multiply("2", "3"));
+        Assert.AreEqual(0, Program.Multiply("0", "5"));
+        Assert.AreEqual(-12, Program.Multiply("-3", "4"));
+    }
+
+    [TestMethod]
+    public void Multiply_Invalid_Hailu()
+    {
+        Assert.ThrowsException<FormatException>(() => Program.Multiply("1", "a"));
+        Assert.ThrowsException<FormatException>(() => Program.Multiply("a", "1"));
+        Assert.ThrowsException<FormatException>(() => Program.Multiply("a", "a"));
+    }
+
+    [TestMethod]
+    public void Multiply_Null_Hailu()
+    {
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Multiply("1", null));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Multiply(null, "1"));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Multiply(null, null));
+    }
+}
+
+[TestClass]
+public class Division
+{
+    [TestMethod]
+    public void Divide_Valid_Hailu()
+    {
+        Assert.AreEqual(2, Program.Divide("6", "3"));
+        Assert.AreEqual(2.5, Program.Divide("5", "2"));
+        Assert.AreEqual(-3, Program.Divide("-9", "3"));
+    }
+
+    [TestMethod]
+    public void Divide_Invalid_Hailu()
+    {
+        Assert.ThrowsException<FormatException>(() => Program.Divide("1", "a"));
+        Assert.ThrowsException<FormatException>(() => Program.Divide("a", "1"));
+        Assert.ThrowsException<FormatException>(() => Program.Divide("a", "a"));
+    }
+
+    [TestMethod]
+    public void Divide_Null_Hailu()
+    {
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Divide("1", null));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Divide(null, "1"));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Divide(null, null));
+    }
+}
+
+[TestClass]
+public class Exponents
+{
+    [TestMethod]
+    public void Power_Valid_Hailu()
+    {
+        Assert.AreEqual(8, Program.Power("2", "3"));
+        Assert.AreEqual(25, Program.Power("5", "2"));
+        Assert.AreEqual(1, Program.Power("7", "0"));
+    }
+
+    [TestMethod]
+    public void Power_Invalid_Hailu()
+    {
+        Assert.ThrowsException<FormatException>(() => Program.Power("1", "a"));
+        Assert.ThrowsException<FormatException>(() => Program.Power("a", "1"));
+        Assert.ThrowsException<FormatException>(() => Program.Power("a", "a"));
+    }
+
+    [TestMethod]
+    public void Power_Null_Hailu()
+    {
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Power("1", null));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Power(null, "1"));
+        Assert.ThrowsException<ArgumentNullException>(() => Program.Power(null, null));
+    }
+}
\ No newline at end of file