diff --git a/lektion-1.org b/lektion-1.org
index 5bb1f0b..cfaeefb 100644
--- a/lektion-1.org
+++ b/lektion-1.org
@@ -225,6 +225,41 @@ void mousePressed() {
 }
 #+end_src
 
+** Datentypen
+*** Mausposition ausgeben
+#+begin_src processing
+void setup(){
+  size(200, 200);
+}
+void draw(){
+  println("x=" + mouseX, "y=" + mouseY);
+}
+#+end_src
+
+*** Halbe Pixel?
+#+begin_src processing
+float x = 0;
+
+void draw() {
+   background(255);
+   ellipse(x, 50, 30, 30);
+   x = x + 0.5;
+}
+#+end_src
+*** Zeichenverkettung
+#+begin_src processing
+String message = "la";
+String moreMessage;
+
+void setup() {
+   println(message);
+}
+
+void draw() {
+  moreMessage = message + moreMessage;
+  println(moreMessage);
+}
+#+end_src
 ** Syntax und Konventionen
 #+begin_src processing
 final int speed=3;
@@ -289,3 +324,16 @@ void draw() {
   moveballs();
 }
 #+end_src
+
+** Arithmetische Operatoren
+*** Muster
+#+begin_src processing
+int x = 0;
+int y = 0;
+
+void draw() {
+   line(x, 0, x, y);
+   x++;
+   y++;
+}
+#+end_src