diff --git a/docs/.vitepress/config.ts b/docs/.vitepress/config.ts
index 338691e8..2f0f34ae 100644
--- a/docs/.vitepress/config.ts
+++ b/docs/.vitepress/config.ts
@@ -117,7 +117,17 @@ export default withMermaid({
                     { text: '配列', link: '/text/chapter-4/array' },
                     { text: '文字列 ②', link: '/text/chapter-4/string' },
                     { text: 'for ②', link: '/text/chapter-4/for-advanced' },
-                    { text: '練習問題', link: '/text/chapter-4/practice/' },
+                    {
+                        text: '練習問題', 
+                        link: '/text/chapter-4/practice/' ,
+                        collapsed: true,
+                        items: [
+                            { text: '4-A1. Fibonatti', link: '/text/chapter-4/practice/fibonatti' },
+                            { text: '4-A2. DO NOT FAIL', link: '/text/chapter-4/practice/do-not-fail' },
+                            { text: '4-A3. lower or UPPER', link: '/text/chapter-4/practice/lower-or-upper' },
+                            { text: '4-B1. Fizz-Buzz 2D', link: '/text/chapter-4/practice/fizz-buzz-2d' },
+                        ]
+                    },
                 ]
             },
             {
@@ -128,16 +138,31 @@ export default withMermaid({
                     { text: '引数', link: '/text/chapter-5/argument' },
                     { text: '返り値', link: '/text/chapter-5/return-value' },
                     { text: '参照渡し', link: '/text/chapter-5/call-by-ref' },
-                    {text: '練習問題', link: '/text/chapter-5/practice/'}
+                    { 
+                        text: '練習問題', 
+                        link: '/text/chapter-5/practice/',
+                        collapsed: true,
+                        items: [
+                            { text: '5-A1. Divide each difficulty', link: '/text/chapter-5/practice/divide-each-difficulty' },
+                            { text: '5-A2. Operator+=', link: '/text/chapter-5/practice/plus-equal' },
+                        ]
+                    }
                 ]
             },
             {
                 text: 'VI. コードの簡易化② - Struct',
                 link: '/text/chapter-6/',
                 items: [
-                    {text: '構造体', link: '/text/chapter-6/struct'},
-                    {text: 'メソッド', link: '/text/chapter-6/method'},
-                    {text: '練習問題', link: '/text/chapter-6/practice/'},
+                    { text: '構造体', link: '/text/chapter-6/struct' },
+                    { text: 'メソッド', link: '/text/chapter-6/method' },
+                    { 
+                        text: '練習問題', 
+                        link: '/text/chapter-6/practice/',
+                        collapsed: true,
+                        items: [
+                            { text: '6-A1. Order', link: '/text/chapter-6/practice/order' },
+                        ]
+                    },
                 ]
             },
             { text: 'VII. おわりに・おまけ', link: '/text/chapter-7/' },
@@ -149,7 +174,15 @@ export default withMermaid({
                     { text: '再帰関数', link: '/text/chapter-8/recursive-function' },
                     { text: '実行時間', link: '/text/chapter-8/exec-time' },
                     { text: 'カプセル化', link: '/text/chapter-8/capsule' },
-                    { text: '練習問題', link: '/text/chapter-8/practice/' },
+                    {
+                        text: '練習問題',
+                        link: '/text/chapter-8/practice/',
+                        collapsed: true,
+                        items: [
+                            { text: 'Capsulated Zer0-Star', link: '/text/chapter-8/practice/capsulate-user' },
+                            { text: 'Exponentation', link: '/text/chapter-8/practice/exponentation' },
+                        ],
+                    },
                 ],
             },
             {
diff --git a/docs/text/chapter-4/practice/do-not-fail.md b/docs/text/chapter-4/practice/do-not-fail.md
index 734ee482..b73f4e8f 100644
--- a/docs/text/chapter-4/practice/do-not-fail.md
+++ b/docs/text/chapter-4/practice/do-not-fail.md
@@ -1,4 +1,4 @@
-# DO NOT FAIL
+# 4-A2. DO NOT FAIL
 
 入力された複数の点数を受け取って、59点以下なら`Failed`と出力しよう。また、`-1`が入力されたら`Passed!`と出力して終了しよう。
 
diff --git a/docs/text/chapter-4/practice/fibonatti.md b/docs/text/chapter-4/practice/fibonatti.md
index e0031964..7cd96255 100644
--- a/docs/text/chapter-4/practice/fibonatti.md
+++ b/docs/text/chapter-4/practice/fibonatti.md
@@ -1,4 +1,4 @@
-# 4-xx. Fibonatti Number
+# 4-A1. Fibonatti Number
 
 正の整数$N$を受け取り、フィボナッチ数列の$N$番目を出力しよう。
 
diff --git a/docs/text/chapter-4/practice/fizz-buzz-2d.md b/docs/text/chapter-4/practice/fizz-buzz-2d.md
index 549c5de4..2a4e54f5 100644
--- a/docs/text/chapter-4/practice/fizz-buzz-2d.md
+++ b/docs/text/chapter-4/practice/fizz-buzz-2d.md
@@ -1,4 +1,4 @@
-# fizz-buzz 2D
+# 4-B1. fizz-buzz 2D
 
 整数 $H, W$ が渡されるので、$H\times W$ の二次元配列 $a_{i,j}\ (1\leq i\leq H, 1\leq j\leq W)$ を出力しよう。
 
diff --git a/docs/text/chapter-4/practice/index.md b/docs/text/chapter-4/practice/index.md
index 42b8b3f9..6f6dc0f2 100644
--- a/docs/text/chapter-4/practice/index.md
+++ b/docs/text/chapter-4/practice/index.md
@@ -1,11 +1,11 @@
-# 練習問題 chapter-4
+# 練習問題 - Chapter 4
 
 ## 練習問題A
 
-- [Fibonatti](fibonatti)
-- [DO NOT FAIL](do-not-fail)
-- [lower or Upper](lower-or-upper)
+- [4-A1. Fibonatti](fibonatti)
+- [4-A2. DO NOT FAIL](do-not-fail)
+- [4-A3. lower or UPPER](lower-or-upper)
 
 ## 練習問題B
 
-- [Fizz-Buzz 2D](fizz-buzz-2d)
+- [4-B1. Fizz-Buzz 2D](fizz-buzz-2d)
diff --git a/docs/text/chapter-4/practice/lower-or-upper.md b/docs/text/chapter-4/practice/lower-or-upper.md
index c19a103f..f5230466 100644
--- a/docs/text/chapter-4/practice/lower-or-upper.md
+++ b/docs/text/chapter-4/practice/lower-or-upper.md
@@ -1,4 +1,4 @@
-# lower or UPPER
+# 4-A3. lower or UPPER
 
 アルファベット1文字が渡されたとき、それが大文字なら"UPPERCASE"、小文字なら"lowercase"と出力しよう。
 
diff --git a/docs/text/chapter-5/practice/divide-each-difficulty.md b/docs/text/chapter-5/practice/divide-each-difficulty.md
index 24a255b1..03497f59 100644
--- a/docs/text/chapter-5/practice/divide-each-difficulty.md
+++ b/docs/text/chapter-5/practice/divide-each-difficulty.md
@@ -1,4 +1,4 @@
-# Divide each difficulty
+# 5-A1. Divide each difficulty
 
 以下の$n \leq 7$を受け取って$n \times n$の行列$a_{i,j}=Fibonatti_{ij}$を出力するプログラムの、フィボナッチ数列の解を求める部分を別の関数`int fibonatti(int index);`に分離してみよう。
 
diff --git a/docs/text/chapter-5/practice/index.md b/docs/text/chapter-5/practice/index.md
index d06ac402..fea9df55 100644
--- a/docs/text/chapter-5/practice/index.md
+++ b/docs/text/chapter-5/practice/index.md
@@ -1,4 +1,4 @@
 # 練習問題 - Chapter 5
 
-- [Divide each difficulty](divide-each-difficulty)
-- [Operator+=](plus-equal)
+- [5-A1. Divide each difficulty](divide-each-difficulty)
+- [5-A2. Operator+=](plus-equal)
diff --git a/docs/text/chapter-5/practice/plus-equal.md b/docs/text/chapter-5/practice/plus-equal.md
index ea1282b4..8d3934ae 100644
--- a/docs/text/chapter-5/practice/plus-equal.md
+++ b/docs/text/chapter-5/practice/plus-equal.md
@@ -1,4 +1,4 @@
-# Operator+=
+# 5-A2. Operator+=
 
 `int`型の`a`と`b`について`a`に`b`を足す操作である
 
diff --git a/docs/text/chapter-6/practice/index.md b/docs/text/chapter-6/practice/index.md
index 70e92fb2..cfc9ca1d 100644
--- a/docs/text/chapter-6/practice/index.md
+++ b/docs/text/chapter-6/practice/index.md
@@ -1,3 +1,3 @@
 # 練習問題 - Chapter 6
 
-- [Order](./order)
\ No newline at end of file
+- [6-A1. Order](./order)
\ No newline at end of file
diff --git a/docs/text/chapter-6/practice/order.md b/docs/text/chapter-6/practice/order.md
index 436a762c..6cc3076a 100644
--- a/docs/text/chapter-6/practice/order.md
+++ b/docs/text/chapter-6/practice/order.md
@@ -1,4 +1,4 @@
-# 6-1. Order
+# 6-A1. Order
 
 以下のような商品の一覧が与えられる。
 
diff --git a/docs/text/chapter-8/practice/index.md b/docs/text/chapter-8/practice/index.md
index c925c125..218be4d5 100644
--- a/docs/text/chapter-8/practice/index.md
+++ b/docs/text/chapter-8/practice/index.md
@@ -1,4 +1,4 @@
-# 練習問題 - Chapter 3
+# 練習問題 - Chapter 8
 
 - [Capsulated Zer0-Star](capsulate-user)
 - [Exponentation](exponentation)
\ No newline at end of file