diff --git a/book/part1_chapter3.md b/book/part1_chapter3.md
index c5147876..98432352 100644
--- a/book/part1_chapter3.md
+++ b/book/part1_chapter3.md
@@ -38,7 +38,7 @@ If we include the states indented:
 ```
 	arr = [64, 34, 25, 12, 22, 11, 90]
 	n = ?, i = ?, j = ?
-set n to lenght of arr which is 7
+set n to length of arr which is 7
 	arr = [64, 34, 25, 12, 22, 11, 90]
 	n = 7, i = ?, j = ?
 set i to 1