diff --git a/material/ab1.pdf b/material/ab1.pdf
index 8d02cbd..d0cb77a 100644
Binary files a/material/ab1.pdf and b/material/ab1.pdf differ
diff --git a/material/ab1.tex b/material/ab1.tex
index df12b98..6d921ea 100644
--- a/material/ab1.tex
+++ b/material/ab1.tex
@@ -104,11 +104,11 @@
 	after skip=10pt
 }
 
-\newtcolorbox{taskbox}[1][]{
+\newtcolorbox{extrataskbox}[1][]{
 	before title={\refstepcounter{commoncounter}}, % KRITISCH: vor dem Titel!
-	title={Aufgabe \thecommoncounter: #1},
+	title={Zusatzaufgabe: #1},
 	colback=white,
-	colframe=white!75!orange,
+	colframe=white!75!red,
 	fonttitle=\bfseries,
 	boxrule=0.6mm,
 	coltitle=black,
@@ -242,12 +242,102 @@
 		\begin{center}
 			\textit{Die Summe des Steins ist die Summe der darüberliegenden Steine. }
 		\end{center}
-		\begin{figure}[H]
+		\begin{figure}[!ht]
 			\centering
-			\includegraphics[width=0.7\linewidth]{pyramide_01}
+			\begin{circuitikz}[x=0.8cm,y=0.8cm]
+				
+				% oberste Reihe
+				\draw[dashed,gray!60] (8.875,16.25) rectangle (10.25,14.875);
+				\node[text=gray!60] at (9.55,15.5625) {0};
+				
+				\draw (10.25,16.25) rectangle (13,14.875);
+				\node[anchor=center] at (11.6,15.5625) {1};
+				
+				\draw[dashed,gray!60] (13,16.25) rectangle (14.375,14.875);
+				\node[text=gray!60] at (13.75,15.5625) {0};
+				
+				% zweite Reihe
+				\draw[dashed,gray!60] (7.5,14.875) rectangle (8.875,13.5);
+				\node[text=gray!60] at (8.175,14.1875) {0};
+				
+				\draw (8.875,14.875) rectangle (11.625,13.5);
+				
+				\draw (11.625,14.875) rectangle (14.375,13.5);
+				
+				\draw[dashed,gray!60] (14.375,14.875) rectangle (15.75,13.5);
+				\node[text=gray!60] at (15,14.1875) {0};
+				
+				% dritte Reihe
+				\draw[dashed,gray!60] (6.125,13.5) rectangle (7.5,12.125);
+				\node[text=gray!60] at (6.8,12.8125) {0};
+				
+				\draw (7.5,13.5) rectangle (10.25,12.125);
+				
+				\draw (10.25,13.5) rectangle (13,12.125);
+				
+				\draw (13,13.5) rectangle (15.75,12.125);
+				
+				\draw[dashed,gray!60] (15.75,13.5) rectangle (17.125,12.125);
+				\node[text=gray!60] at (16.375,12.8125) {0};
+				
+				% unterste Reihe
+				\draw[dashed,gray!60] (4.75,12.125) rectangle (6.125,10.75);
+				\node[text=gray!60] at (5.425,11.4375) {0};
+				
+				\draw (6.125,12.125) rectangle (8.875,10.75);
+				
+				\draw (8.875,12.125) rectangle (11.625,10.75);
+				
+				\draw (11.625,12.125) rectangle (14.375,10.75);
+				
+				\draw (14.375,12.125) rectangle (17.125,10.75);
+				
+				\draw[dashed,gray!60] (17.125,12.125) rectangle (18.5,10.75);
+				\node[text=gray!60] at (17.875,11.4375) {0};
+				
+			\end{circuitikz}
 		\end{figure}
 		
+		\item Berechne die Steine der Pyramide:
+			\begin{figure}[!ht]
+				\centering
+				\begin{circuitikz}[x=0.8cm,y=0.8cm]
+					
+					\draw (10.25,16.25) rectangle (13,14.875);
+					\node at (10.875,15.5625) {$\binom{0}{0}=$};
+					
+					\draw (8.875,14.875) rectangle (11.625,13.5);
+					\node at (9.5,14.1875) {$\binom{1}{0}=$};
+					
+					\draw (11.625,14.875) rectangle (14.375,13.5);
+					\node at (12.25,14.1875) {$\binom{1}{1}=$};
+					
+					\draw (10.25,13.5) rectangle (13,12.125);
+					\node at (10.875,12.8125) {$\binom{2}{0}=$};
+					
+					\draw (7.5,13.5) rectangle (10.25,12.125);
+					\node at (8.125,12.8125) {$\binom{2}{1}=$};
+					
+					\draw (13,13.5) rectangle (15.75,12.125);
+					\node at (13.625,12.8125) {$\binom{2}{2}=$};
+					
+					\draw (11.625,12.125) rectangle (14.375,10.75);
+					\node at (12.25,11.4375) {$\binom{3}{0}=$};
+					
+					\draw (8.875,12.125) rectangle (11.625,10.75);
+					\node at (9.5,11.4375) {$\binom{3}{1}=$};
+					
+					\draw (6.125,12.125) rectangle (8.875,10.75);
+					\node at (6.75,11.4375) {$\binom{3}{2}=$};
+					
+					\draw (14.375,12.125) rectangle (17.125,10.75);
+					\node at (15,11.4375) {$\binom{3}{3}=$};
+				\end{circuitikz}
+			\end{figure}
 	\end{enumerate}
+	\begin{extrataskbox}
+		Entwirf einen Computeralgorithmus, der den Binomialkoeffizienten berechnet, ohne dass dieser die Fakultät benutzt!
+	\end{extrataskbox}
 	
 	\label{LastPage}
 \end{document}