diff --git a/CHANGELOG.md b/CHANGELOG.md
index 72a2829..2ba2602 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+# 0.4.3
+
+- Number tower now has to be filled out instead of being calculated automatically.
+- Number tower now counts seconds.
+
 # 0.4.2
 
 - update `self_update` dependency, which is now able to replace running files on Windows.
diff --git a/Cargo.lock b/Cargo.lock
index dec77b3..850714e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -520,7 +520,7 @@ dependencies = [
 
 [[package]]
 name = "kopfrechner"
-version = "0.4.2"
+version = "0.4.3"
 dependencies = [
  "colored",
  "dialoguer",
diff --git a/Cargo.toml b/Cargo.toml
index 5018c1a..7a1784b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,7 @@
 name = "kopfrechner"
 authors = ["Wolfgang Schwendtbauer"]
 repository = "https://github.com/Woife5/kopfrechner"
-version = "0.4.2"
+version = "0.4.3"
 edition = "2021"
 
 [dependencies]
diff --git a/src/modes/mod.rs b/src/modes/mod.rs
index 2ef6bd0..bd64ee8 100644
--- a/src/modes/mod.rs
+++ b/src/modes/mod.rs
@@ -20,7 +20,7 @@ fn get_number_input(prompt: String) -> Option<usize> {
             _ => match input_text.parse::<usize>() {
                 Ok(v) => return Some(v),
                 Err(_) => {
-                    println!("\rNot a valid number, try again.");
+                    println!("\rNot a valid number, try again. (Enter 'q' to quit)");
                     continue;
                 }
             },
diff --git a/src/modes/multiplication.rs b/src/modes/multiplication.rs
index 28d734c..9331da9 100644
--- a/src/modes/multiplication.rs
+++ b/src/modes/multiplication.rs
@@ -76,8 +76,8 @@ pub fn run(range: RangeInclusive<u16>) {
     }
 
     println!("\n{}", "Results:".bold());
-    println!("{}: {}", "Correct".green().italic(), correct,);
-    println!("{}: {}", "Incorrect".red().italic(), incorrect,);
+    println!("{}: {}", "Correct".green().italic(), correct);
+    println!("{}: {}", "Incorrect".red().italic(), incorrect);
     println!(
         "{}: {:.2}s",
         "Average time".italic(),
diff --git a/src/modes/number_tower.rs b/src/modes/number_tower.rs
index 96e80b2..272d1fd 100644
--- a/src/modes/number_tower.rs
+++ b/src/modes/number_tower.rs
@@ -1,4 +1,4 @@
-use colored::Colorize;
+use colored::{ColoredString, Colorize};
 
 use super::get_number_input;
 
@@ -10,20 +10,52 @@ pub fn prepare_and_run() {
     }
 }
 
+fn run_iteration(current: &usize, padding: ColoredString) -> Result<(), ()> {
+    let input = match get_number_input("".to_string()) {
+        Some(v) => v,
+        None =>  return Err(()),
+    };
+
+    let input_str = format!("{:>20}", input);
+    let result_text = if input == *current {
+        "Correct!".green()
+    } else {
+        format!("Wrong! ({})", current).red()
+    };
+
+    // Move cursor up one line and clear the line
+    print!("\x1B[1A\x1B[2K\r");
+    println!("{:>20} {} {}", input_str, padding, result_text);
+    Ok(())
+}
+
 pub fn run(start: usize) {
+    let start_time = std::time::Instant::now();
     let mut current = start;
 
-    for i in 2..=9 {
+    let padding = format!("| × {}", 2).yellow();
+    println!("{:>20} {}", current, padding);
+    current *= 2;
+
+    for i in 3..=9 {
         let padding = format!("| × {}", i).yellow();
-        println!("{:>20} {}", current, padding);
+        match run_iteration(&current, padding) {
+            Err(_) => return,
+            _ => (),
+        };
         current *= i;
     }
 
     for i in 2..=9 {
         let padding = format!("| ÷ {}", i).yellow();
-        println!("{:>20} {}", current, padding);
+        match run_iteration(&current, padding) {
+            Err(_) => return,
+            _ => (),
+        };
         current /= i;
     }
 
     println!("{:>20} {}", current, "| Result".yellow());
+    let elapsed = start_time.elapsed();
+    println!("took {}", elapsed.as_secs());
 }