diff --git a/src/Ch00/CodeDemo.cpp b/src/Ch00/CodeDemo.cpp
index 2613d2c3..613e0ee0 100644
--- a/src/Ch00/CodeDemo.cpp
+++ b/src/Ch00/CodeDemo.cpp
@@ -1,5 +1,5 @@
 // Learning C++ 
-// Exercise 00_03
+// Exercise 00_03 with modifications
 // Using the exercise files on GitHub, by Eduardo Corpeño 
 
 #include <iostream>
diff --git a/src/Ch02/02_03b/CodeDemo.cpp b/src/Ch02/02_03b/CodeDemo.cpp
index 8b365648..90518785 100644
--- a/src/Ch02/02_03b/CodeDemo.cpp
+++ b/src/Ch02/02_03b/CodeDemo.cpp
@@ -4,9 +4,27 @@
 
 #include <iostream>
 
+int a, b = 5; // single line comment
+
+/* Multi
+* line
+* comment */
+
 int main(){
-    std::cout << "Hi There!" << std::endl;
-    
+    bool my_flag;
+    a = 7;
+    my_flag = false;
+    std::cout << "a = " << a << std::endl;
+    std::cout << "b = " << b << std::endl;
+    std::cout << "flag = " << my_flag << std::endl;
+    my_flag = true;
+    std::cout << "flag = " << my_flag << std::endl;
+    std::cout << "a + b = " << a + b << std::endl;
+    std::cout << "b - a = " << b - a << std::endl;
+    unsigned int positive;
+    positive = b - a;
+    std::cout << "b - a (unsigned) = " << positive << std::endl;
+
     std::cout << std::endl << std::endl;
     return (0);
 }
diff --git a/src/Ch02/02_05b/CodeDemo.cpp b/src/Ch02/02_05b/CodeDemo.cpp
index eed63d20..b6104f1e 100644
--- a/src/Ch02/02_05b/CodeDemo.cpp
+++ b/src/Ch02/02_05b/CodeDemo.cpp
@@ -6,7 +6,22 @@
 #include <typeinfo>
 
 int main(){
-    
+    auto a = 8;
+    auto b = 12345678901;
+    auto c = 3.14f;
+    auto d = 3.14;
+    auto e = true;
+    auto f = 'd';
+    auto g = "C++ rocks!";
+
+    std::cout << "The type of a is " << typeid(a).name() << std::endl;
+    std::cout << "The type of b is " << typeid(b).name() << std::endl;
+    std::cout << "The type of c is " << typeid(c).name() << std::endl;
+    std::cout << "The type of d is " << typeid(d).name() << std::endl;
+    std::cout << "The type of e is " << typeid(e).name() << std::endl;
+    std::cout << "The type of f is " << typeid(f).name() << std::endl;
+    std::cout << "The type of g is " << typeid(g).name() << std::endl;
+
     std::cout << std::endl << std::endl;
     return (0);
 }