diff --git a/src/index.js b/src/index.js
index f16abeb..a7b3c8b 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,5 +1,15 @@
 const factorial = (number) => {
-    
+  
+  if (number === 0) {
+    return 1
   }
 
-  module.exports = factorial;
\ No newline at end of file
+  let factorial = 1
+
+  for(let i = 1; i <= number; i++){
+    factorial = factorial * i
+  }
+  return factorial
+}
+
+module.exports = factorial;
\ No newline at end of file