diff --git a/calculator.py b/calculator.py
index 90f5426..544f099 100644
--- a/calculator.py
+++ b/calculator.py
@@ -1,31 +1,39 @@
 def add(a, b):
-    pass
+    return a + b
 
 
 def subtract(a, b):
-	pass
+	return a - b
 
 
 def multiply(a, b):
-    pass
+    return a * b
 
 
 def divide(a, b):
-    pass
+    return a / b
 
 
 def pow(a, b):
-    pass
+    return a ** b
 
 
 def abs(a):
-    pass
+    if a < 0:
+         return -a
+    return a
 
 
 def mod(a, b):
-    pass
+    return a % b
 
 
 if __name__ == "__main__":
-    # 간단한 테스트 코드
-    pass
\ No newline at end of file
+    print(add(1,2))
+    print(subtract(1,2))
+    print(multiply(1,2))
+    print(divide(1,2))
+    print(pow(1,2))
+    print(abs(-1))
+    print(mod(1,2))
+    
\ No newline at end of file