diff --git a/exercises/00_intro/intro2.rs b/exercises/00_intro/intro2.rs
index c6cb645..03e376e 100644
--- a/exercises/00_intro/intro2.rs
+++ b/exercises/00_intro/intro2.rs
@@ -1,4 +1,4 @@
 fn main() {
     // TODO: Fix the code to print "Hello world!".
-    printline!("Hello world!");
+    println!("Hello world!");
 }
diff --git a/exercises/01_variables/variables1.rs b/exercises/01_variables/variables1.rs
index f83b44d..ec1bcac 100644
--- a/exercises/01_variables/variables1.rs
+++ b/exercises/01_variables/variables1.rs
@@ -1,6 +1,6 @@
 fn main() {
     // TODO: Add the missing keyword.
-    x = 5;
+    let x = 5;
 
     println!("x has the value {x}");
 }
diff --git a/exercises/01_variables/variables2.rs b/exercises/01_variables/variables2.rs
index e2a3603..d10390d 100644
--- a/exercises/01_variables/variables2.rs
+++ b/exercises/01_variables/variables2.rs
@@ -1,6 +1,6 @@
 fn main() {
     // TODO: Change the line below to fix the compiler error.
-    let x;
+    let x: i32 = 65;
 
     if x == 10 {
         println!("x is ten!");
diff --git a/exercises/01_variables/variables3.rs b/exercises/01_variables/variables3.rs
index 06f35bb..eefd283 100644
--- a/exercises/01_variables/variables3.rs
+++ b/exercises/01_variables/variables3.rs
@@ -1,6 +1,6 @@
 fn main() {
     // TODO: Change the line below to fix the compiler error.
-    let x: i32;
+    let x: i32 = 52;
 
     println!("Number {x}");
 }
diff --git a/exercises/01_variables/variables4.rs b/exercises/01_variables/variables4.rs
index 6c138b1..90d4ef0 100644
--- a/exercises/01_variables/variables4.rs
+++ b/exercises/01_variables/variables4.rs
@@ -1,6 +1,6 @@
 // TODO: Fix the compiler error.
 fn main() {
-    let x = 3;
+    let mut x = 3;
     println!("Number {x}");
 
     x = 5; // Don't change this line