diff --git a/programs/lst22/main b/programs/lst22/main
deleted file mode 100755
index 573f886..0000000
Binary files a/programs/lst22/main and /dev/null differ
diff --git a/programs/printf-formats/main b/programs/printf-formats/main
deleted file mode 100755
index b705c1c..0000000
Binary files a/programs/printf-formats/main and /dev/null differ
diff --git a/programs/printf-formats/main-p-1-1 b/programs/printf-formats/main-p-1-1
deleted file mode 100755
index 98bba39..0000000
Binary files a/programs/printf-formats/main-p-1-1 and /dev/null differ
diff --git a/programs/printf-formats/main-p-1-2 b/programs/printf-formats/main-p-1-2
deleted file mode 100755
index 79f1055..0000000
Binary files a/programs/printf-formats/main-p-1-2 and /dev/null differ
diff --git a/programs/printf-formats/main-p-1-2.c b/programs/printf-formats/main-p-1-2.c
deleted file mode 100644
index 4e3281b..0000000
--- a/programs/printf-formats/main-p-1-2.c
+++ /dev/null
@@ -1,14 +0,0 @@
-#include <stdio.h>
-
-int main(void) {
-    int n = 10;
-    double x = 25.3;
-
-    printf("Int n: "); scanf("%d", &n);
-    printf("Doble n: "); scanf("%f", &x);
-
-    printf("Integer n is %lf\n", n);
-    printf("Double percision floating point decimal x is %f\n", x);
-
-    return 0;
-}
diff --git a/programs/printf-formats/main-p-2-1 b/programs/printf-formats/main-p-2-1
deleted file mode 100755
index 106164c..0000000
Binary files a/programs/printf-formats/main-p-2-1 and /dev/null differ
diff --git a/programs/printf-formats/main-p-2-2 b/programs/printf-formats/main-p-2-2
deleted file mode 100755
index 2bc25f9..0000000
Binary files a/programs/printf-formats/main-p-2-2 and /dev/null differ
diff --git a/programs/printf-formats/main-p-3-1 b/programs/printf-formats/main-p-3-1
deleted file mode 100755
index 32e66a1..0000000
Binary files a/programs/printf-formats/main-p-3-1 and /dev/null differ
diff --git a/programs/printf-formats/main-p-3-2 b/programs/printf-formats/main-p-3-2
deleted file mode 100755
index b5f9d24..0000000
Binary files a/programs/printf-formats/main-p-3-2 and /dev/null differ
diff --git a/programs/printf-formats/main-p-4-1 b/programs/printf-formats/main-p-4-1
deleted file mode 100755
index 7564b02..0000000
Binary files a/programs/printf-formats/main-p-4-1 and /dev/null differ
diff --git a/programs/printf-formats/main-p-4-2 b/programs/printf-formats/main-p-4-2
deleted file mode 100755
index 4942d1e..0000000
Binary files a/programs/printf-formats/main-p-4-2 and /dev/null differ
diff --git a/programs/printf-formats/main-p-1-1.c b/programs/printf-formats/main-p1-f.c
similarity index 83%
rename from programs/printf-formats/main-p-1-1.c
rename to programs/printf-formats/main-p1-f.c
index e9ff506..d348b99 100644
--- a/programs/printf-formats/main-p-1-1.c
+++ b/programs/printf-formats/main-p1-f.c
@@ -5,7 +5,7 @@ int main(void) {
     double x;
 
     printf("Int n: "); scanf("%d", &n);
-    printf("Doble n: "); scanf("%f", &x);
+    printf("Double x: "); scanf("%lf", &x);
 
     printf("Integer n is %f\n", n);
     printf("Double percision floating point decimal x is %f\n", x);
diff --git a/programs/printf-formats/main-p1-lf.c b/programs/printf-formats/main-p1-lf.c
new file mode 100644
index 0000000..0a94d3c
--- /dev/null
+++ b/programs/printf-formats/main-p1-lf.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int main(void) {
+    int n;
+    double x;
+
+    printf("Int n: "); scanf("%d", &n);
+    printf("Double x: "); scanf("%lf", &x);
+
+    printf("Integer n is %d\n", n);
+    printf("Double percision floating point decimal x is %f\n", x);
+
+    return 0;
+}
diff --git a/programs/printf-formats/main-p-2-1.c b/programs/printf-formats/main-p2-d.c
similarity index 83%
rename from programs/printf-formats/main-p-2-1.c
rename to programs/printf-formats/main-p2-d.c
index 6e3b34b..ffa26f3 100644
--- a/programs/printf-formats/main-p-2-1.c
+++ b/programs/printf-formats/main-p2-d.c
@@ -5,7 +5,7 @@ int main(void) {
     double x;
 
     printf("Int n: "); scanf("%d", &n);
-    printf("Doble n: "); scanf("%f", &x);
+    printf("Double x: "); scanf("%lf", &x);
 
     printf("Integer n is %d\n", n);
     printf("Double percision floating point decimal x is %d\n", x);
diff --git a/programs/printf-formats/main-p-2-2.c b/programs/printf-formats/main-p2-lf.c
similarity index 83%
rename from programs/printf-formats/main-p-2-2.c
rename to programs/printf-formats/main-p2-lf.c
index 70a434c..362c4df 100644
--- a/programs/printf-formats/main-p-2-2.c
+++ b/programs/printf-formats/main-p2-lf.c
@@ -5,7 +5,7 @@ int main(void) {
     double x;
 
     printf("Int n: "); scanf("%d", &n);
-    printf("Doble n: "); scanf("%f", &x);
+    printf("Double x: "); scanf("%lf", &x);
 
     printf("Integer n is %d\n", n);
     printf("Double percision floating point decimal x is %lf\n", x);
diff --git a/programs/printf-formats/main-p-3-1.c b/programs/printf-formats/main-s1-f.c
similarity index 83%
rename from programs/printf-formats/main-p-3-1.c
rename to programs/printf-formats/main-s1-f.c
index 1ff2db8..ed9eb61 100644
--- a/programs/printf-formats/main-p-3-1.c
+++ b/programs/printf-formats/main-s1-f.c
@@ -5,7 +5,7 @@ int main(void) {
     double x;
 
     printf("Int n: "); scanf("%f", &n);
-    printf("Doble n: "); scanf("%f", &x);
+    printf("Double x: "); scanf("%lf", &x);
 
     printf("Integer n is %d\n", n);
     printf("Double percision floating point decimal x is %f\n", x);
diff --git a/programs/printf-formats/main-p-3-2.c b/programs/printf-formats/main-s1-lf.c
similarity index 83%
rename from programs/printf-formats/main-p-3-2.c
rename to programs/printf-formats/main-s1-lf.c
index 159ffe1..57d6754 100644
--- a/programs/printf-formats/main-p-3-2.c
+++ b/programs/printf-formats/main-s1-lf.c
@@ -5,7 +5,7 @@ int main(void) {
     double x;
 
     printf("Int n: "); scanf("%lf", &n);
-    printf("Doble n: "); scanf("%f", &x);
+    printf("Double x: "); scanf("%lf", &x);
 
     printf("Integer n is %d\n", n);
     printf("Double percision floating point decimal x is %f\n", x);
diff --git a/programs/printf-formats/main-p-4-2.c b/programs/printf-formats/main-s2-d.c
similarity index 83%
rename from programs/printf-formats/main-p-4-2.c
rename to programs/printf-formats/main-s2-d.c
index 14666da..2b1feab 100644
--- a/programs/printf-formats/main-p-4-2.c
+++ b/programs/printf-formats/main-s2-d.c
@@ -5,7 +5,7 @@ int main(void) {
     double x;
 
     printf("Int n: "); scanf("%d", &n);
-    printf("Doble n: "); scanf("%lf", &x);
+    printf("Double x: "); scanf("%d", &x);
 
     printf("Integer n is %d\n", n);
     printf("Double percision floating point decimal x is %f\n", x);
diff --git a/programs/printf-formats/main-p-4-1.c b/programs/printf-formats/main-s2-f.c
similarity index 83%
rename from programs/printf-formats/main-p-4-1.c
rename to programs/printf-formats/main-s2-f.c
index 7a85d70..b3fb489 100644
--- a/programs/printf-formats/main-p-4-1.c
+++ b/programs/printf-formats/main-s2-f.c
@@ -5,7 +5,7 @@ int main(void) {
     double x;
 
     printf("Int n: "); scanf("%d", &n);
-    printf("Doble n: "); scanf("%d", &x);
+    printf("Double x: "); scanf("%f", &x);
 
     printf("Integer n is %d\n", n);
     printf("Double percision floating point decimal x is %f\n", x);
diff --git a/programs/printf-formats/main.c b/programs/printf-formats/main.c
index 31f43ca..0a94d3c 100644
--- a/programs/printf-formats/main.c
+++ b/programs/printf-formats/main.c
@@ -5,7 +5,7 @@ int main(void) {
     double x;
 
     printf("Int n: "); scanf("%d", &n);
-    printf("Doble n: "); scanf("%f", &x);
+    printf("Double x: "); scanf("%lf", &x);
 
     printf("Integer n is %d\n", n);
     printf("Double percision floating point decimal x is %f\n", x);
diff --git a/programs/printf-formats/test.txt b/programs/printf-formats/test.txt
new file mode 100644
index 0000000..e74a6f5
--- /dev/null
+++ b/programs/printf-formats/test.txt
@@ -0,0 +1,4 @@
+10
+25.3
+
+
diff --git a/programs/prog1/main b/programs/prog1/main
deleted file mode 100755
index f018d4e..0000000
Binary files a/programs/prog1/main and /dev/null differ
diff --git a/programs/prog2/main b/programs/prog2/main
deleted file mode 100755
index c912b68..0000000
Binary files a/programs/prog2/main and /dev/null differ
diff --git a/programs/rev3dig/main b/programs/rev3dig/main
deleted file mode 100755
index 03bad8d..0000000
Binary files a/programs/rev3dig/main and /dev/null differ
diff --git a/section/printf-formats.tex b/section/printf-formats.tex
new file mode 100644
index 0000000..dba99ed
--- /dev/null
+++ b/section/printf-formats.tex
@@ -0,0 +1,65 @@
+\section{\texttt{double}型と\texttt{printf}関数・\texttt{scanf}関数の書式}
+
+\defaultlistingstyle
+\lstinputlisting[language=C, title={変更元のソースコード}]{../programs/printf-formats/main.c}
+
+上記のソースコードについて、\texttt{printf}関数と\texttt{scanf}関数の書式を次のように変更していく：
+
+\begin{itemize}
+    \item 第一の\texttt{printf}関数の書式を\texttt{\%f}にする
+    \item 第一の\texttt{printf}関数の書式を\texttt{\%lf}にする
+    \item 第二の\texttt{printf}関数の書式を\texttt{\%d}にする
+    \item 第二の\texttt{printf}関数の書式を\texttt{\%lf}にする
+    \item 第一の\texttt{scanf}関数の書式を\texttt{\%f}にする
+    \item 第一の\texttt{scanf}関数の書式を\texttt{\%lf}にする
+    \item 第二の\texttt{scanf}関数の書式を\texttt{\%d}にする
+    \item 第二の\texttt{scanf}関数の書式を\texttt{\%f}にする
+\end{itemize}
+
+\subsection{\texttt{main-p1-f}}
+
+\begin{center}
+    \includegraphics[width=\textwidth]{./assets/printf-formats/main-p1-f}
+\end{center}
+
+\subsection{\texttt{main-p1-lf}}
+
+\begin{center}
+    \includegraphics[width=\textwidth]{./assets/printf-formats/main-p1-lf}
+\end{center}
+
+\subsection{\texttt{main-p2-d}}
+
+\begin{center}
+    \includegraphics[width=\textwidth]{./assets/printf-formats/main-p2-d}
+\end{center}
+
+\subsection{\texttt{main-p2-lf}}
+
+\begin{center}
+    \includegraphics[width=\textwidth]{./assets/printf-formats/main-p2-lf}
+\end{center}
+
+\subsection{\texttt{main-s1-f}}
+
+\begin{center}
+    \includegraphics[width=\textwidth]{./assets/printf-formats/main-p3-f}
+\end{center}
+
+\subsection{\texttt{main-s1-lf}}
+
+\begin{center}
+    \includegraphics[width=\textwidth]{./assets/printf-formats/main-p3-lf}
+\end{center}
+
+\subsection{\texttt{main-s2-d}}
+
+\begin{center}
+    \includegraphics[width=\textwidth]{./assets/printf-formats/main-p4-d}
+\end{center}
+
+\subsection{\texttt{main-s2-f}}
+
+\begin{center}
+    \includegraphics[width=\textwidth]{./assets/printf-formats/main-p4-f}
+\end{center}