diff --git a/2021/src/day1.rs b/2021/src/day1.rs
index 0008b4d..b308c31 100644
--- a/2021/src/day1.rs
+++ b/2021/src/day1.rs
@@ -3,7 +3,7 @@ use color_eyre::eyre;
 use crate::lib::ParseLines;
 
 
-fn run(data: &str) -> eyre::Result<()> {
+pub fn run(data: &str) -> eyre::Result<(i32, i32)> {
     let mut single_increases = 0;
     let mut window_increases = 0;
     let mut prev = (None, None, None);
@@ -25,7 +25,5 @@ fn run(data: &str) -> eyre::Result<()> {
         prev = (prev.1, prev.2, Some(n));
     }
 
-    println!("One: {}", single_increases);
-    println!("Two: {}", window_increases);
-    Ok(())
+    Ok((single_increases, window_increases))
 }
diff --git a/2021/src/day2.rs b/2021/src/day2.rs
index 8291935..c544639 100644
--- a/2021/src/day2.rs
+++ b/2021/src/day2.rs
@@ -74,13 +74,11 @@ fn part2(commands: &Vec<MoveCmd>) -> i32 {
 }
 
 
-pub fn run(data: &str) -> eyre::Result<()> {
+pub fn run(data: &str) -> eyre::Result<(i32, i32)> {
     let mut commands = Vec::new();
     for res in data.parse_lines::<MoveCmd>() {
         commands.push(res?);
     }
 
-    println!("One: {}", part1(&commands));
-    println!("Two: {}", part2(&commands));
-    Ok(())
+    Ok((part1(&commands), part2(&commands)))
 }
diff --git a/2021/src/day3.rs b/2021/src/day3.rs
index 3b1a9c7..2250ca2 100644
--- a/2021/src/day3.rs
+++ b/2021/src/day3.rs
@@ -57,13 +57,11 @@ fn part2(numbers: &Vec<u16>) -> u64 {
 
 
 
-pub fn run(data: &str) -> eyre::Result<()> {
+pub fn run(data: &str) -> eyre::Result<(u64, u64)> {
     let mut nums = Vec::new();
     for line in data.lines() {
         nums.push(u16::from_str_radix(line, 2)?);
     }
 
-    println!("One: {}", part1(&nums));
-    println!("Two: {}", part2(&nums));
-    Ok(())
+    Ok((part1(&nums), part2(&nums)))
 }
\ No newline at end of file
diff --git a/2021/src/day4.rs b/2021/src/day4.rs
index bf24d97..debb702 100644
--- a/2021/src/day4.rs
+++ b/2021/src/day4.rs
@@ -111,20 +111,21 @@ impl Board {
         }
     }
 
-    fn score(&self) -> eyre::Result<usize> {
+    fn score(&self) -> eyre::Result<isize> {
         let bingo_time = match self.bingo_time {
             Some(t) => t,
             None => return Err(eyre!("Cannot find the score of a non-winning board")),
         };
-        let mut total = 0usize;
+        let mut total = 0;
         for row in self.squares {
             for sq in row {
                 if sq.draw_time.is_some() && sq.draw_time.unwrap() > bingo_time {
-                    total += sq.value as usize;
+                    total += sq.value as isize;
                 }
             }
         }
-        Ok(total * self.bingo_value.unwrap() as usize)
+        let multiplier = self.bingo_value.unwrap() as isize;
+        Ok(total * multiplier)
     }
 }
 
@@ -190,9 +191,8 @@ fn part1(boards: &[Board]) -> eyre::Result<Board> {
 }
 
 
-pub fn run(data: &str) -> eyre::Result<()> {
+pub fn run(data: &str) -> eyre::Result<(isize, isize)> {
     let boards = load(data)?;
     let winner = part1(&boards)?;
-    println!("One: {}", winner.score()?);
-    Ok(())
+    Ok((winner.score()?, 0))
 }
diff --git a/2021/src/main.rs b/2021/src/main.rs
index 19ca81a..c104471 100644
--- a/2021/src/main.rs
+++ b/2021/src/main.rs
@@ -9,20 +9,26 @@ mod day4;
 
 fn main() -> eyre::Result<()> {
     let data = load("data/04.txt")?;
+
     let start = Instant::now();
-    day4::run(&data)?;
+    let (one, two) = day4::run(&data)?;
     let (dur, unit) = format_ns(start.elapsed().as_nanos());
-    println!("Completed in {}{}", dur, unit);
+
+    let precision = 2.0 - dur.log10().floor();
+    println!(
+        "One: {0}\nTwo: {1}\nCompleted in {2:.4$}{3}",
+        one, two, dur, unit, precision as usize
+    );
     Ok(())
 }
 
 
-fn format_ns(ns: u128) -> (u128, &'static str) {
+fn format_ns(ns: u128) -> (f64, &'static str) {
     const UNITS: [&str; 4] = ["ns", "us", "ms", "s"];
-    let mut display_n = ns;
+    let mut display_n = ns as f64; // 
     let mut unit_idx = 0;
-    while display_n > 1000 && unit_idx < 4 {
-        display_n /= 1000;
+    while display_n > 1000.0 && unit_idx < 4 {
+        display_n /= 1000.0;
         unit_idx += 1
     }