diff --git a/01_getting-started/02_numeral-systems/02_binary/main.go b/01_getting-started/02_numeral-systems/02_binary/main.go
index 4e540f92..96356c0b 100644
--- a/01_getting-started/02_numeral-systems/02_binary/main.go
+++ b/01_getting-started/02_numeral-systems/02_binary/main.go
@@ -3,5 +3,5 @@ package main
 import "fmt"
 
 func main() {
-	fmt.Printf("%d - %b \n", 42, 42)
+	fmt.Printf("%d - %b \n", 42, 42) // explains how it works: https://pkg.go.dev/fmt
 }