diff --git a/src/minirechner.c b/src/minirechner.c
index b5bf37b..036ebbe 100644
--- a/src/minirechner.c
+++ b/src/minirechner.c
@@ -4,4 +4,9 @@
 //addieren
 float addieren(float a, float b) {
     return a + b;
+}
+
+//subtrahieren
+float subtrahieren(float a, float b) {
+    return a - b;
 }
\ No newline at end of file
diff --git a/src/minirechner.h b/src/minirechner.h
index 63695c7..0a61c42 100644
--- a/src/minirechner.h
+++ b/src/minirechner.h
@@ -2,5 +2,6 @@
 #define MINIRECHNER_H
 
 float addieren(float a, float b);
+float subtrahieren(float a, float b);
 
 #endif // MINIRECHNER_H
diff --git a/test/test_minirechner.c b/test/test_minirechner.c
index cacd21b..cba19de 100644
--- a/test/test_minirechner.c
+++ b/test/test_minirechner.c
@@ -36,4 +36,12 @@ void test_minitaschenrechner_0_plus_2(void)
     float result = addieren(0, 2);
     TEST_ASSERT_EQUAL(2, result);
 }
+
+// test subtraktion
+void test_minitaschenrechner_5_minus_2(void)
+{
+    float result = subtrahieren(5, 2);
+    TEST_ASSERT_EQUAL(3, result);
+}
+
 #endif // TEST