diff --git a/chapter05.tex b/chapter05.tex
index d2f21e4..2a7cab2 100644
--- a/chapter05.tex
+++ b/chapter05.tex
@@ -510,7 +510,7 @@ the lower-right corner and count the number of such paths.
 \item
 running time: 483 seconds
 \item
-recursive calls: 76 billion
+number of recursive calls: 76 billion
 \end{itemize}
 
 \subsubsection{Optimization 1}
@@ -564,7 +564,7 @@ and finally multiply the number of the solutions by two.
 \item
 running time: 244 seconds
 \item
-recursive calls: 38 billion
+number of recursive calls: 38 billion
 \end{itemize}
 
 \subsubsection{Optimization 2}
@@ -593,7 +593,7 @@ immediately if we reach the lower-right square too early.
 \item
 running time: 119 seconds
 \item
-recursive calls: 20 billion
+number of recursive calls: 20 billion
 \end{itemize}
 
 \subsubsection{Optimization 3}
@@ -625,7 +625,7 @@ It turns out that this optimization is very useful:
 \item
 running time: 1.8 seconds
 \item
-recursive calls: 221 million
+number of recursive calls: 221 million
 \end{itemize}
 
 \subsubsection{Optimization 4}
@@ -662,7 +662,7 @@ very efficient:
 \item
 running time: 0.6 seconds
 \item
-recursive calls: 69 million
+number of recursive calls: 69 million
 \end{itemize}
 
 ~\\