diff --git a/.all-contributorsrc b/.all-contributorsrc
index 26fd5c9..d3f0c2c 100644
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@@ -1146,6 +1146,15 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "Fointard",
+      "name": "Fointard",
+      "avatar_url": "https://avatars.githubusercontent.com/u/9333398?v=4",
+      "profile": "https://github.com/Fointard",
+      "contributions": [
+        "content"
+      ]
     }
   ],
   "contributorsPerLine": 8,
diff --git a/AUTHORS.md b/AUTHORS.md
index 1dc5647..9b388bb 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -164,6 +164,7 @@ authors.
     <td align="center"><a href="https://github.com/ragreenburg"><img src="https://avatars.githubusercontent.com/u/24358100?v=4?s=100" width="100px;" alt=""/><br /><sub><b>ragreenburg</b></sub></a><br /><a href="#content-ragreenburg" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/stevenfukase"><img src="https://avatars.githubusercontent.com/u/66785624?v=4?s=100" width="100px;" alt=""/><br /><sub><b>stevenfukase</b></sub></a><br /><a href="#content-stevenfukase" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/J-S-Kim"><img src="https://avatars.githubusercontent.com/u/17569303?v=4?s=100" width="100px;" alt=""/><br /><sub><b>J-S-Kim</b></sub></a><br /><a href="#content-J-S-Kim" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/Fointard"><img src="https://avatars.githubusercontent.com/u/9333398?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Fointard</b></sub></a><br /><a href="#content-Fointard" title="Content">🖋</a></td>
   </tr>
 </table>
 
diff --git a/exercises/conversions/using_as.rs b/exercises/conversions/using_as.rs
index 821309e..f3f745f 100644
--- a/exercises/conversions/using_as.rs
+++ b/exercises/conversions/using_as.rs
@@ -8,7 +8,7 @@
 // I AM NOT DONE
 
 fn average(values: &[f64]) -> f64 {
-    let total = values.iter().fold(0.0, |a, b| a + b);
+    let total = values.iter().sum::<f64>();
     total / values.len()
 }
 
diff --git a/exercises/standard_library_types/arc1.rs b/exercises/standard_library_types/arc1.rs
index d167380..f60061e 100644
--- a/exercises/standard_library_types/arc1.rs
+++ b/exercises/standard_library_types/arc1.rs
@@ -32,12 +32,7 @@ fn main() {
     for offset in 0..8 {
         let child_numbers = // TODO
         joinhandles.push(thread::spawn(move || {
-            let mut i = offset;
-            let mut sum = 0;
-            while i < child_numbers.len() {
-                sum += child_numbers[i];
-                i += 8;
-            }
+            let sum: u32 = child_numbers.iter().filter(|n| *n % 8 == offset).sum();
             println!("Sum of offset {} is {}", offset, sum);
         }));
     }