diff --git a/src/primzahl/main.c b/src/primzahl/main.c
new file mode 100644
index 0000000..8480010
--- /dev/null
+++ b/src/primzahl/main.c
@@ -0,0 +1,19 @@
+#include "primzahl.h"
+#include "../userinput.h"
+#include <stdio.h>
+
+int main() {
+    // set the smallest possible input
+    int minInput = 0;
+
+    //get user input
+    int num = usergetd("Enter a positive number: ", minInput, NULL);
+
+    //check if its a prime number or not
+    if (primzahl(num))
+        printf("%d is a prime number.\n", num);
+    else
+        printf("%d is not a prime number.\n", num);
+
+    return 0;
+}
\ No newline at end of file
diff --git a/src/primzahl/primzahl.c b/src/primzahl/primzahl.c
new file mode 100644
index 0000000..e8fd70b
--- /dev/null
+++ b/src/primzahl/primzahl.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int primzahl(int num) {
+	//for the case zero or one
+	if (num <= 1)
+		return 0;
+
+	//checking if there are any other divider
+	for (int i = 2; i < num; i++) {
+		if (num % i == 0)
+			return 0;
+	}
+	//if none were found return true
+	return 1;
+}
\ No newline at end of file
diff --git a/src/primzahl/primzahl.h b/src/primzahl/primzahl.h
new file mode 100644
index 0000000..0f6cfc2
--- /dev/null
+++ b/src/primzahl/primzahl.h
@@ -0,0 +1,6 @@
+#ifndef PRIMZAHL_H
+#define PRIMZAHL_H
+
+int primzahl(int num);
+
+#endif
\ No newline at end of file
diff --git a/test/primzahl/test_primzahl.c b/test/primzahl/test_primzahl.c
new file mode 100644
index 0000000..2276ce9
--- /dev/null
+++ b/test/primzahl/test_primzahl.c
@@ -0,0 +1,17 @@
+#include "unity.h"
+#include "primzahl.h"
+
+void setUP(){}
+void tearDown(){}
+
+void test_primzahl() {
+	TEST_ASSERT_TRUE(primzahl(2));	// 2 is a prime number
+	TEST_ASSERT_TRUE(primzahl(3));	// 3 is a prime number
+	TEST_ASSERT_TRUE(primzahl(5));	// 5 is a prime number
+	TEST_ASSERT_TRUE(primzahl(7));	// 7 is a prime number
+	TEST_ASSERT_FALSE(primzahl(1));	// 1 is not a prime number
+	TEST_ASSERT_FALSE(primzahl(4));	// 4 is not a prime number
+	TEST_ASSERT_FALSE(primzahl(6));	// 6 is not a prime number
+	TEST_ASSERT_FALSE(primzahl(9));	// 9 is not a prime number
+
+}
\ No newline at end of file