diff --git a/src/test/c/test_berechnung.c b/src/test/c/test_berechnung.c
index 81db07d..b84757a 100644
--- a/src/test/c/test_berechnung.c
+++ b/src/test/c/test_berechnung.c
@@ -22,6 +22,48 @@ void test_berechnung_2_convertsToDigit(void)
     result = convert(2);
 
     /* assert */
+    TEST_ASSERT_EQUAL_STRING (expected, result);
+}
+
+void test_berechnung_11_convertsToDigits(void)
+{
+    char* result;
+    char expected[] = "11\n";
+
+    result = convert(11);
+
+    TEST_ASSERT_EQUAL_STRING (expected, result);
+}
+
+void test_berechnung_10_convertsTo_buzz(void)
+{
+    char* result;
+    char expected[] = "buzz\n";
+
+    result = convert(10);
+
+    TEST_ASSERT_EQUAL_STRING (expected, result);
+}
+
+void test_berechnung_20_30_is_10(void)
+{
+    int result;
+    int expected = 10;
+
+    result = gcd(20, 30);
+
+    TEST_ASSERT_EQUAL_INT (expected, result);
+}
+
+
+void test_berechnung_20_30_is_11_fails(void)
+{
+    int result;
+    int expected = 11;
+
+    result = gcd(20, 30);
+
+    TEST_ASSERT_EQUAL_INT (expected, result);
 }
 
 #endif // TEST