diff --git a/src/arithmeticDivision.c b/src/arithmeticDivision.c
new file mode 100644
index 0000000..7cdfc7e
--- /dev/null
+++ b/src/arithmeticDivision.c
@@ -0,0 +1,17 @@
+#include "arithmeticDivision.h"
+#include <stdio.h>
+#include <limits.h>
+#include <stdlib.h>
+
+int* division_integer(int dividend, int divisor) {
+    if(divisor == 0) {
+        return NULL;
+    }
+    // Overflow protection
+    if (dividend == INT_MIN && divisor == -1) {
+        return NULL;
+    }
+    int* result = malloc(sizeof(int));
+    *result = dividend / divisor;
+    return result;
+}
\ No newline at end of file
diff --git a/src/arithmeticDivision.h b/src/arithmeticDivision.h
new file mode 100644
index 0000000..e4080b7
--- /dev/null
+++ b/src/arithmeticDivision.h
@@ -0,0 +1,6 @@
+#ifndef THEADMIRALS_ARITHMETICDIVISION_H
+#define THEADMIRALS_ARITHMETICDIVISION_H
+
+int* division_integer(int, int);
+
+#endif //THEADMIRALS_ARITHMETICDIVISION_H
diff --git a/src/arithmeticSubtraction.c b/src/arithmeticSubtraction.c
new file mode 100644
index 0000000..f8a7eb5
--- /dev/null
+++ b/src/arithmeticSubtraction.c
@@ -0,0 +1,10 @@
+
+#include "arithmeticSubtraction.h"
+
+#include <stdlib.h>
+
+int* subtraction_integer(int a, int b) {
+    int* result= malloc(sizeof (int));
+    *result=a - b;
+    return result;
+}
diff --git a/src/arithmeticSubtraction.h b/src/arithmeticSubtraction.h
new file mode 100644
index 0000000..5a36ba5
--- /dev/null
+++ b/src/arithmeticSubtraction.h
@@ -0,0 +1,7 @@
+
+#ifndef THEADMIRALS_ARITHMETICSUBTRACTION_H
+#define THEADMIRALS_ARITHMETICSUBTRACTION_H
+
+int* subtraction_integer(int a, int b);
+
+#endif //THEADMIRALS_ARITHMETICSUBTRACTION_H
diff --git a/src/logarithmicFunctions.c b/src/logarithmicFunctions.c
new file mode 100644
index 0000000..e940cb5
--- /dev/null
+++ b/src/logarithmicFunctions.c
@@ -0,0 +1,18 @@
+#include "logarithmicFunctions.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+double* logarithm_two_integer(int base, int num){
+    if(base <= 1 || num <= 0){
+        return NULL;
+    }
+
+    double* result = (double*)malloc(sizeof(double));
+    if (result == NULL) {
+        return NULL;
+    }
+
+    *result = log(num) / log(base);
+    return result;
+}
diff --git a/src/logarithmicFunctions.h b/src/logarithmicFunctions.h
new file mode 100644
index 0000000..c13f29d
--- /dev/null
+++ b/src/logarithmicFunctions.h
@@ -0,0 +1,6 @@
+#ifndef THEADMIRALS_LOGARITHMICFUNCTIONS_H
+#define THEADMIRALS_LOGARITHMICFUNCTIONS_H
+
+double* logarithm_two_integer(int base, int num);
+
+#endif //THEADMIRALS_LOGARITHMICFUNCTIONS_H
diff --git a/team.md b/team.md
index 9389aab..317f693 100644
--- a/team.md
+++ b/team.md
@@ -1,3 +1,4 @@
 - Eric Bagus, fdai7812
 - Leon Wolf, fdai7845
-- Sandro Welte, fdai7728
\ No newline at end of file
+- Sandro Welte, fdai7728
+- Jonas Zitzmann, fdai7791
\ No newline at end of file
diff --git a/test/test_arithmeticDivision.c b/test/test_arithmeticDivision.c
new file mode 100644
index 0000000..6428ea0
--- /dev/null
+++ b/test/test_arithmeticDivision.c
@@ -0,0 +1,19 @@
+#include "../src/arithmeticDivision.h"
+#include "unity.h"
+#include "limits.h"
+
+void setUp(void) {
+    // set stuff up here
+}
+
+void tearDown(void) {
+    // clean stuff up here
+}
+
+
+void test_arithmeticDivision_numberdividedbynumberequalsnumber(void) {
+    int expectedResult = 2;
+    int* result;
+    result = division_integer(14, 7);
+    TEST_ASSERT_EQUAL_INT(expectedResult, *result);
+}
diff --git a/test/test_arithmeticSubtraction.c b/test/test_arithmeticSubtraction.c
new file mode 100644
index 0000000..26d05c4
--- /dev/null
+++ b/test/test_arithmeticSubtraction.c
@@ -0,0 +1,18 @@
+#include "../src/arithmeticSubtraction.h"
+#include "unity.h"
+#include "limits.h"
+
+void setUp(void) {
+    // set stuff up here
+}
+
+void tearDown(void) {
+    // clean stuff up here
+}
+void test_arithmeticSubtraction_subractionoftwonumbers(void) {
+    int expectedResult = 7;
+    int* result;
+    result = subtraction_integer(14, 7);
+    TEST_ASSERT_EQUAL_INT(expectedResult, *result);
+}
+
diff --git a/test/test_logarithmicFunctions.c b/test/test_logarithmicFunctions.c
new file mode 100644
index 0000000..512696e
--- /dev/null
+++ b/test/test_logarithmicFunctions.c
@@ -0,0 +1,18 @@
+#include "../src/logarithmicFunctions.h"
+#include "unity.h"
+#include "limits.h"
+
+void setUp(void) {
+    // set stuff up here
+}
+
+void tearDown(void) {
+    // clean stuff up here
+}
+
+void test_logarithmicFunctions_logarithmiccalculation(void){
+    double expectedResult = 3.000000;
+    double* result;
+    result = logarithm_two_integer(2,8);
+    TEST_ASSERT_EQUAL_DOUBLE(expectedResult, *result);
+}
\ No newline at end of file