From f8a9211740561b1e177e5e36c1b1a6ce923492e8 Mon Sep 17 00:00:00 2001
From: Steve Klabnik <steve@steveklabnik.com>
Date: Mon, 18 Aug 2014 15:38:47 -0400
Subject: [PATCH 1/2] Explain modulo in the guide.

Fixes #15954
---
 src/doc/guide.md | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/doc/guide.md b/src/doc/guide.md
index 2593ddc556b..194205c561e 100644
--- a/src/doc/guide.md
+++ b/src/doc/guide.md
@@ -1888,8 +1888,15 @@ fn main() {
 
 The first thing we changed was to `use std::rand`, as the docs
 explained.  We then added in a `let` expression to create a variable binding
-named `secret_number`, and we printed out its result. Let's try to compile
-this using `cargo build`:
+named `secret_number`, and we printed out its result.
+
+Also, you may wonder why we are using `%` on the result of `rand::random()`.
+This operator is called 'modulo', and it returns the remainder of a division.
+By taking the modulo of the result of `rand::random()`, we're limiting the
+values to be between 0 and 99. Then, we add one to the result, making it from 1
+to 100.
+
+Let's try to compile this using `cargo build`:
 
 ```{notrust,no_run}
 $ cargo build

From c88feffde4f5043adf07a6837026f228e20b67e6 Mon Sep 17 00:00:00 2001
From: Steve Klabnik <steve@steveklabnik.com>
Date: Mon, 18 Aug 2014 15:50:42 -0400
Subject: [PATCH 2/2] Make comment about small bias in %.

Fixes #16354.
---
 src/doc/guide.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/doc/guide.md b/src/doc/guide.md
index 194205c561e..f6fa57fe143 100644
--- a/src/doc/guide.md
+++ b/src/doc/guide.md
@@ -1894,7 +1894,8 @@ Also, you may wonder why we are using `%` on the result of `rand::random()`.
 This operator is called 'modulo', and it returns the remainder of a division.
 By taking the modulo of the result of `rand::random()`, we're limiting the
 values to be between 0 and 99. Then, we add one to the result, making it from 1
-to 100.
+to 100. Using modulo can give you a very, very small bias in the result, but
+for this example, it is not important.
 
 Let's try to compile this using `cargo build`: