diff --git a/build/test/cache/test_add.c b/build/test/cache/test_add.c
new file mode 100644
index 0000000..26907b6
--- /dev/null
+++ b/build/test/cache/test_add.c
@@ -0,0 +1,51 @@
+#include "src/main/c/Template/game100.h"
+#include "/var/lib/gems/3.0.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h"
+
+
+
+
+
+
+void setUp(void){
+
+
+
+}
+
+void tearDown(void){
+
+}
+
+
+
+
+
+void test_add(void){
+
+
+
+    int num1 = 10;
+
+    int num2 = 5;
+
+    int result;
+
+    int addition = num1 + num2;
+
+
+
+
+
+     result = addition;
+
+
+
+
+
+    UnityAssertEqualNumber((UNITY_INT)((15)), (UNITY_INT)((result)), (
+
+   ((void *)0)
+
+   ), (UNITY_UINT)(24), UNITY_DISPLAY_STYLE_INT);
+
+}
diff --git a/build/test/dependencies/test_add.d b/build/test/dependencies/test_add.d
new file mode 100644
index 0000000..4a84e70
--- /dev/null
+++ b/build/test/dependencies/test_add.d
@@ -0,0 +1,4 @@
+build/test/out/c/test_add.o: test/Calculator/test_add.c \
+ /var/lib/gems/3.0.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h \
+ /var/lib/gems/3.0.0/gems/ceedling-0.31.1/vendor/unity/src/unity_internals.h \
+ src/main/c/Template/game100.h
diff --git a/build/test/dependencies/test_add_runner.d b/build/test/dependencies/test_add_runner.d
new file mode 100644
index 0000000..e3f0886
--- /dev/null
+++ b/build/test/dependencies/test_add_runner.d
@@ -0,0 +1,3 @@
+build/test/out/c/test_add_runner.o: build/test/runners/test_add_runner.c \
+ /var/lib/gems/3.0.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h \
+ /var/lib/gems/3.0.0/gems/ceedling-0.31.1/vendor/unity/src/unity_internals.h
diff --git a/build/test/out/c/calculator.o b/build/test/out/c/calculator.o
index b0c6aae..9bb982f 100644
Binary files a/build/test/out/c/calculator.o and b/build/test/out/c/calculator.o differ
diff --git a/build/test/out/c/test_add.o b/build/test/out/c/test_add.o
new file mode 100644
index 0000000..5e3770d
Binary files /dev/null and b/build/test/out/c/test_add.o differ
diff --git a/build/test/out/c/test_add_runner.o b/build/test/out/c/test_add_runner.o
new file mode 100644
index 0000000..f018a39
Binary files /dev/null and b/build/test/out/c/test_add_runner.o differ
diff --git a/build/test/out/test_add.out b/build/test/out/test_add.out
new file mode 100755
index 0000000..24da445
Binary files /dev/null and b/build/test/out/test_add.out differ
diff --git a/build/test/out/test_cbrt.out b/build/test/out/test_cbrt.out
index a2da86b..0b7105f 100755
Binary files a/build/test/out/test_cbrt.out and b/build/test/out/test_cbrt.out differ
diff --git a/build/test/out/test_divide.out b/build/test/out/test_divide.out
index 9f48e14..9fa276d 100755
Binary files a/build/test/out/test_divide.out and b/build/test/out/test_divide.out differ
diff --git a/build/test/out/test_factorial.out b/build/test/out/test_factorial.out
index bb6cc10..ac29a81 100755
Binary files a/build/test/out/test_factorial.out and b/build/test/out/test_factorial.out differ
diff --git a/build/test/out/test_log.out b/build/test/out/test_log.out
index 75852f7..4c40fb4 100755
Binary files a/build/test/out/test_log.out and b/build/test/out/test_log.out differ
diff --git a/build/test/out/test_mod.out b/build/test/out/test_mod.out
index 9cc3169..956dc8c 100755
Binary files a/build/test/out/test_mod.out and b/build/test/out/test_mod.out differ
diff --git a/build/test/out/test_pow.out b/build/test/out/test_pow.out
index a9bcd93..8c03b38 100755
Binary files a/build/test/out/test_pow.out and b/build/test/out/test_pow.out differ
diff --git a/build/test/out/test_sqrt.out b/build/test/out/test_sqrt.out
index 1301f23..bd75723 100755
Binary files a/build/test/out/test_sqrt.out and b/build/test/out/test_sqrt.out differ
diff --git a/build/test/preprocess/files/test_add.c b/build/test/preprocess/files/test_add.c
new file mode 100644
index 0000000..26907b6
--- /dev/null
+++ b/build/test/preprocess/files/test_add.c
@@ -0,0 +1,51 @@
+#include "src/main/c/Template/game100.h"
+#include "/var/lib/gems/3.0.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h"
+
+
+
+
+
+
+void setUp(void){
+
+
+
+}
+
+void tearDown(void){
+
+}
+
+
+
+
+
+void test_add(void){
+
+
+
+    int num1 = 10;
+
+    int num2 = 5;
+
+    int result;
+
+    int addition = num1 + num2;
+
+
+
+
+
+     result = addition;
+
+
+
+
+
+    UnityAssertEqualNumber((UNITY_INT)((15)), (UNITY_INT)((result)), (
+
+   ((void *)0)
+
+   ), (UNITY_UINT)(24), UNITY_DISPLAY_STYLE_INT);
+
+}
diff --git a/build/test/preprocess/includes/test_add.c b/build/test/preprocess/includes/test_add.c
new file mode 100644
index 0000000..e60bf2a
--- /dev/null
+++ b/build/test/preprocess/includes/test_add.c
@@ -0,0 +1,3 @@
+---
+- "/var/lib/gems/3.0.0/gems/ceedling-0.31.1/vendor/unity/src/unity.h"
+- src/main/c/Template/game100.h
diff --git a/build/test/results/test_add.pass b/build/test/results/test_add.pass
new file mode 100644
index 0000000..009f601
--- /dev/null
+++ b/build/test/results/test_add.pass
@@ -0,0 +1,18 @@
+---
+:source:
+  :path: test/Calculator
+  :file: test_add.c
+:successes:
+- :test: test_add
+  :line: 13
+  :message: ''
+  :unity_test_time: 0
+:failures: []
+:ignores: []
+:counts:
+  :total: 1
+  :passed: 1
+  :failed: 0
+  :ignored: 0
+:stdout: []
+:time: 0.006868249998660758
diff --git a/build/test/results/test_cbrt.pass b/build/test/results/test_cbrt.pass
index e95950c..5181d7c 100644
--- a/build/test/results/test_cbrt.pass
+++ b/build/test/results/test_cbrt.pass
@@ -15,4 +15,4 @@
   :failed: 0
   :ignored: 0
 :stdout: []
-:time: 0.0006476099952124059
+:time: 0.0062123289972078055
diff --git a/build/test/results/test_divide.pass b/build/test/results/test_divide.pass
index 421094a..bddd3e8 100644
--- a/build/test/results/test_divide.pass
+++ b/build/test/results/test_divide.pass
@@ -15,4 +15,4 @@
   :failed: 0
   :ignored: 0
 :stdout: []
-:time: 0.007046165002975613
+:time: 0.006226740020792931
diff --git a/build/test/results/test_factorial.pass b/build/test/results/test_factorial.pass
index 97232a1..e91b02f 100644
--- a/build/test/results/test_factorial.pass
+++ b/build/test/results/test_factorial.pass
@@ -15,4 +15,4 @@
   :failed: 0
   :ignored: 0
 :stdout: []
-:time: 0.0032789550023153424
+:time: 0.006363478023558855
diff --git a/build/test/results/test_log.pass b/build/test/results/test_log.pass
index 2416b02..77260d8 100644
--- a/build/test/results/test_log.pass
+++ b/build/test/results/test_log.pass
@@ -15,4 +15,4 @@
   :failed: 0
   :ignored: 0
 :stdout: []
-:time: 0.0031624000112060457
+:time: 0.006499917013570666
diff --git a/build/test/results/test_mod.pass b/build/test/results/test_mod.pass
index 75d7c0c..0106b0c 100644
--- a/build/test/results/test_mod.pass
+++ b/build/test/results/test_mod.pass
@@ -15,4 +15,4 @@
   :failed: 0
   :ignored: 0
 :stdout: []
-:time: 0.0031652229954488575
+:time: 0.00630686100339517
diff --git a/build/test/results/test_multiply.pass b/build/test/results/test_multiply.pass
index 8299cd9..4a34455 100644
--- a/build/test/results/test_multiply.pass
+++ b/build/test/results/test_multiply.pass
@@ -15,4 +15,4 @@
   :failed: 0
   :ignored: 0
 :stdout: []
-:time: 0.003240023012040183
+:time: 0.004303659981815144
diff --git a/build/test/results/test_pow.pass b/build/test/results/test_pow.pass
index f2c83d1..31cacd6 100644
--- a/build/test/results/test_pow.pass
+++ b/build/test/results/test_pow.pass
@@ -19,4 +19,4 @@
   :failed: 0
   :ignored: 0
 :stdout: []
-:time: 0.0032584719883743674
+:time: 0.006403419014532119
diff --git a/build/test/results/test_sqrt.pass b/build/test/results/test_sqrt.pass
index c6ff18b..4c256e7 100644
--- a/build/test/results/test_sqrt.pass
+++ b/build/test/results/test_sqrt.pass
@@ -15,4 +15,4 @@
   :failed: 0
   :ignored: 0
 :stdout: []
-:time: 0.0032074050104711205
+:time: 0.006328894000034779
diff --git a/build/test/runners/test_add_runner.c b/build/test/runners/test_add_runner.c
new file mode 100644
index 0000000..eab12b8
--- /dev/null
+++ b/build/test/runners/test_add_runner.c
@@ -0,0 +1,81 @@
+/* AUTOGENERATED FILE. DO NOT EDIT. */
+
+/*=======Automagically Detected Files To Include=====*/
+#include "unity.h"
+
+int GlobalExpectCount;
+int GlobalVerifyOrder;
+char* GlobalOrderError;
+
+/*=======External Functions This Runner Calls=====*/
+extern void setUp(void);
+extern void tearDown(void);
+extern void test_add(void);
+
+
+/*=======Mock Management=====*/
+static void CMock_Init(void)
+{
+  GlobalExpectCount = 0;
+  GlobalVerifyOrder = 0;
+  GlobalOrderError = NULL;
+}
+static void CMock_Verify(void)
+{
+}
+static void CMock_Destroy(void)
+{
+}
+
+/*=======Test Reset Options=====*/
+void resetTest(void);
+void resetTest(void)
+{
+  tearDown();
+  CMock_Verify();
+  CMock_Destroy();
+  CMock_Init();
+  setUp();
+}
+void verifyTest(void);
+void verifyTest(void)
+{
+  CMock_Verify();
+}
+
+/*=======Test Runner Used To Run Each Test=====*/
+static void run_test(UnityTestFunction func, const char* name, UNITY_LINE_TYPE line_num)
+{
+    Unity.CurrentTestName = name;
+    Unity.CurrentTestLineNumber = line_num;
+#ifdef UNITY_USE_COMMAND_LINE_ARGS
+    if (!UnityTestMatches())
+        return;
+#endif
+    Unity.NumberOfTests++;
+    UNITY_CLR_DETAILS();
+    UNITY_EXEC_TIME_START();
+    CMock_Init();
+    if (TEST_PROTECT())
+    {
+        setUp();
+        func();
+    }
+    if (TEST_PROTECT())
+    {
+        tearDown();
+        CMock_Verify();
+    }
+    CMock_Destroy();
+    UNITY_EXEC_TIME_STOP();
+    UnityConcludeTest();
+}
+
+/*=======MAIN=====*/
+int main(void)
+{
+  UnityBegin("test_add.c");
+  run_test(test_add, "test_add", 13);
+
+  return UnityEnd();
+}
diff --git a/src/main/c/Calculator/calculator.c b/src/main/c/Calculator/calculator.c
index 6854565..a27f433 100644
--- a/src/main/c/Calculator/calculator.c
+++ b/src/main/c/Calculator/calculator.c
@@ -18,7 +18,7 @@ double    sqrt(double num1);
 double cbrt(num1); 
 int multiply (int num1,int num2);
 double divide (double num1, double num2);
-
+int add (int num1, int num2);
 
     int calculator() {
     int choice;
@@ -188,3 +188,7 @@ double divide(double num1, double num2){
     double division = num1 / num2;
     return division;
 }
+int add(int num1, int num2){
+    int addition = num1 + num2;
+    return addition;
+}
diff --git a/src/main/c/Calculator/calculator.h b/src/main/c/Calculator/calculator.h
index 9e123ee..eb4f04d 100644
--- a/src/main/c/Calculator/calculator.h
+++ b/src/main/c/Calculator/calculator.h
@@ -10,4 +10,5 @@ double    sqrt(double num1);
 double cbrt(double num1);
 int multiply(int num1,int num2);
 double divide(double num1,double num2);
+int add(int num1 ,int num2);
 #endif
diff --git a/test/Calculator/test_add.c b/test/Calculator/test_add.c
new file mode 100644
index 0000000..57e6f55
--- /dev/null
+++ b/test/Calculator/test_add.c
@@ -0,0 +1,28 @@
+#ifdef TEST
+#include "unity.h"
+#include "game100.h"
+
+
+void setUp(void){
+    //Wenn Funktion Vorraussetzungen braucht
+}
+void tearDown(void){
+}
+
+
+void test_add(void){
+    /* arrange */
+    int num1 = 10;
+    int num2 = 5;
+    int result;
+    int addition = num1 + num2;
+
+    /* act */
+     result = addition;
+
+    /* assert */
+    TEST_ASSERT_EQUAL_INT(15, result);// 10 + 5 = 15
+}
+
+
+#endif // TEST