diff --git a/I2_Dobble/makefile b/I2_Dobble/makefile
index 1f15f75..f2acc1f 100644
--- a/I2_Dobble/makefile
+++ b/I2_Dobble/makefile
@@ -1,5 +1,6 @@
 CC = gcc
-FLAGS = -g -Wall -lm
+CFLAGS = -g -Wall
+LDFLAGS = -lm
 
 ifeq ($(OS),Windows_NT)
 	include makefile_windows.variables
@@ -27,7 +28,7 @@ doble_initial:
 program_obj_files = stack.o bintree.o numbers.o timer.o highscore.o
 
 doble : main.o $(program_obj_files)
-	$(CC) $(FLAGS) $^ -o doble
+	$(CC) $(FLAGS) $(LDFLAGS) $^ -o doble
 
 $(program_obj_filesobj_files): %.o: %.c
 	$(CC) -c $(FLAGS) $^ -o $@
@@ -35,15 +36,21 @@ $(program_obj_filesobj_files): %.o: %.c
 # --------------------------
 # Unit Tests
 # --------------------------
-unitTests:
-	echo "needs to be implemented"
+unitTests: numbersTest
+	./runNumbersTest
+
+numbersTest: numbers.o bintree.o numbersTest.o $($(unityfolder)/unity.c)
+	$(CC) $(FLAGS) $(LDFLAGS) $^ -o $@
+
+%.o: %.c
+	$(CC) -c $(FLAGS) $< -o $@
 
 # --------------------------
 # Clean
 # --------------------------
 clean:
 ifeq ($(OS),Windows_NT)
-	del /f *.o doble
+	del /f *.o doble runNumbersTest
 else
-	rm -f *.o doble
+	rm -f *.o doble runNumbersTest
 endif
\ No newline at end of file
diff --git a/I2_Dobble/numbersTest.c b/I2_Dobble/numbersTest.c
new file mode 100644
index 0000000..4bca72d
--- /dev/null
+++ b/I2_Dobble/numbersTest.c
@@ -0,0 +1,89 @@
+#include "numbers.h"
+#include "unity.h"
+#include "unity_internals.h"
+
+void test_createNumbers_no_null(void) 
+{
+    unsigned int *arr = createNumbers(10);
+    TEST_ASSERT_NOT_NULL(arr);
+    free(arr);
+}
+
+void test_createNumbers_has_exactly_one_duplicate(void) 
+{
+    unsigned int len = 100;
+    unsigned int *arr = createNumbers(len);
+    TEST_ASSERT_NOT_NULL(arr);
+
+    unsigned int dup = getDuplicate(arr, len);
+    TEST_ASSERT_NOT_EQUAL(0, dup);
+
+    int count = 0;
+    for (unsigned int i = 0; i < len; i++) 
+    {
+        if (arr[i] == dup) 
+            count++;
+    }
+    
+    TEST_ASSERT_EQUAL(2, count);
+
+    free(arr);
+}
+
+void test_createNumbers_has_correct_value_range(void)
+{
+    unsigned int len = 10;
+    unsigned int *arr = createNumbers(len);
+    TEST_ASSERT_NOT_NULL(arr);
+
+    // Check all numbers are within valid range (1 to 2*len)
+    for (unsigned int i = 0; i < len; i++)
+    {
+        TEST_ASSERT_TRUE(arr[i] >= 1);
+        TEST_ASSERT_TRUE(arr[i] <= 2 * len);
+    }
+
+    free(arr);
+}
+
+void test_getDuplicate_returns_correct_value(void) 
+{
+    unsigned int arr[6] = {4, 1, 7, 7, 3, 2};
+    unsigned int d = getDuplicate(arr, 6);
+    TEST_ASSERT_EQUAL_UINT(7, d);
+}
+
+void test_complete_function_of_numbers(void) 
+{
+    unsigned int len = 50;
+    unsigned int *arr = createNumbers(len);
+    TEST_ASSERT_NOT_NULL(arr);
+
+    unsigned int d1 = getDuplicate(arr, len);
+    TEST_ASSERT_NOT_EQUAL(0, d1);
+
+    int count = 0;
+
+    for (unsigned int i = 0; i < len; i++) 
+    {
+        if (arr[i] == d1) 
+            count++;
+    }
+
+    TEST_ASSERT_EQUAL(2, count);
+
+    free(arr);
+}
+
+int main(void) 
+{
+    UNITY_BEGIN();
+
+    RUN_TEST(test_createNumbers_no_null);
+    RUN_TEST(test_createNumbers_has_exactly_one_duplicate);
+    RUN_TEST(test_createNumbers_has_correct_value_range);
+    RUN_TEST(test_getDuplicate_returns_correct_value);
+    RUN_TEST(test_complete_function_of_numbers);
+
+    return UNITY_END();
+}
\ No newline at end of file