diff --git a/go/03-modules/go.mod b/go/03-modules/go.mod
new file mode 100644
index 0000000..e56e608
--- /dev/null
+++ b/go/03-modules/go.mod
@@ -0,0 +1,5 @@
+module gitty.informatik.hs-mannheim.de/steger/pr3-code/go/03-modules
+
+go 1.25.0
+
+require github.com/google/uuid v1.6.0
diff --git a/go/03-modules/go.sum b/go/03-modules/go.sum
new file mode 100644
index 0000000..7790d7c
--- /dev/null
+++ b/go/03-modules/go.sum
@@ -0,0 +1,2 @@
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
diff --git a/go/03-modules/main.go b/go/03-modules/main.go
index 7905807..923a1d4 100644
--- a/go/03-modules/main.go
+++ b/go/03-modules/main.go
@@ -1,5 +1,27 @@
 package main
 
-func main() {
+import (
+	"fmt"
 
+	// importing the myMath package with an alias mm. This allows us to use mm instead of myMath to access the functions in the package.
+	// go packages are imported using their full path, which is the path to the package relative to the GOPATH or module root. .
+	mm "gitty.informatik.hs-mannheim.de/steger/pr3-code/go/03-modules/myMath"
+
+	// the underscore is used to import a package solely for its side effects (i.e., the init function).
+	// This is useful when you want to initialize a package but do not need to access any of its exported functions or variables.
+	// _ "gitty.informatik.hs-mannheim.de/steger/pr3-code/go/03-modules/myMath"
+
+	// importing a third-party package from GitHub. This package provides functions for generating UUIDs (Universally Unique Identifiers).
+	// To use this package, you need to run go get github.com/google/uuid to download and install the package in your Go workspace.
+	// Alternatively, you can run go mod tidy to automatically download and install any missing dependencies based on the imports in your code.
+	"github.com/google/uuid"
+	//run go get github.com/google/uuid
+	//or go mod tidy => go.sum
+)
+
+func main() {
+	fmt.Println(mm.Add(1, 2))
+
+	id := uuid.New()
+	fmt.Println("Generated UUID:", id)
 }
diff --git a/go/03-modules/myMath/math.go b/go/03-modules/myMath/math.go
index e69de29..f348cd8 100644
--- a/go/03-modules/myMath/math.go
+++ b/go/03-modules/myMath/math.go
@@ -0,0 +1,27 @@
+package myMath
+
+import "fmt"
+
+// init is a special function that is called automatically when the package is imported. It is used to initialize the package
+// and can be used to set up any necessary state or perform any necessary setup before the package is used.
+func init() {
+	fmt.Println("initializing myMath")
+}
+
+// functions that start with an uppercase letter are exported and can be accessed from outside the package
+func Add(a, b int) int {
+	return a + b
+}
+
+// functions that start with a lowercase letter are not exported and cannot be accessed from outside the package
+func greater(a, b int) bool {
+	return a > b
+}
+
+func Min(a, b int) int {
+	if greater(a, b) {
+		return b
+	} else {
+		return a
+	}
+}
diff --git a/go/03-modules/myMath/math_test.go b/go/03-modules/myMath/math_test.go
new file mode 100644
index 0000000..cf3fe11
--- /dev/null
+++ b/go/03-modules/myMath/math_test.go
@@ -0,0 +1,35 @@
+package myMath_test
+
+import (
+	"testing"
+
+	"gitty.informatik.hs-mannheim.de/steger/pr3-code/go/03-modules/myMath"
+)
+
+func TestAdd(t *testing.T) {
+	sum := myMath.Add(2, 3)
+	if sum != 5 {
+		t.Errorf("Add(2,3) = %v, want %v", sum, 5)
+	}
+}
+
+func TestMin(t *testing.T) {
+	type args struct {
+		in0 int
+		in1 int
+	}
+	tests := []struct {
+		name string
+		args args
+		want int
+	}{
+		{"first greater", args{3, 2}, 2},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := myMath.Min(tt.args.in0, tt.args.in1); got != tt.want {
+				t.Errorf("Min() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}