diff --git a/math_keyboard/lib/src/foundation/keyboard_button.dart b/math_keyboard/lib/src/foundation/keyboard_button.dart
index a79c901..882d722 100644
--- a/math_keyboard/lib/src/foundation/keyboard_button.dart
+++ b/math_keyboard/lib/src/foundation/keyboard_button.dart
@@ -211,7 +211,18 @@ final functionKeyboard = [
     ),
   ],
   [
-    const PageButtonConfig(flex: 3),
+    // const PageButtonConfig(flex: 3),
+    const BasicKeyboardButtonConfig(
+      label: '[',
+      value: '[',
+      highlighted: true,
+      keyboardCharacters: ['['],
+    ),const BasicKeyboardButtonConfig(
+      label: ']',
+      value: ']',
+      highlighted: true,
+      keyboardCharacters: [']'],
+    ),
     const BasicKeyboardButtonConfig(
       label: '(',
       value: '(',
@@ -224,9 +235,9 @@ final functionKeyboard = [
       highlighted: true,
       keyboardCharacters: [')'],
     ),
-    PreviousButtonConfig(),
-    NextButtonConfig(),
-    DeleteButtonConfig(),
+    // PreviousButtonConfig(),
+    // NextButtonConfig(),
+    // DeleteButtonConfig(),
   ],
 ];
 
@@ -270,11 +281,11 @@ final standardKeyboard = [
     DeleteButtonConfig(),
   ],
   [
-    const PageButtonConfig(),
-    _digitButtons[0],
+    // const PageButtonConfig(),
     PreviousButtonConfig(),
+    _digitButtons[0],
     NextButtonConfig(),
-    SubmitButtonConfig(),
+    SubmitButtonConfig(flex: 4),
   ],
 ];
 
diff --git a/math_keyboard/lib/src/widgets/math_keyboard.dart b/math_keyboard/lib/src/widgets/math_keyboard.dart
index ccf16fa..eb07461 100644
--- a/math_keyboard/lib/src/widgets/math_keyboard.dart
+++ b/math_keyboard/lib/src/widgets/math_keyboard.dart
@@ -140,7 +140,7 @@ class MathKeyboard extends StatelessWidget {
                       color: Color(0xFFCCCCCC))
                     ]
                   ),
-                  padding: EdgeInsets.only(top: 16.0),
+                  padding: EdgeInsets.only(top: 16.0, left: 16.0, right: 16.0),
                   child: _KeyboardBody(
                     insetsState: insetsState,
                     slideAnimation:
@@ -150,7 +150,7 @@ class MathKeyboard extends StatelessWidget {
                       child: Center(
                         child: ConstrainedBox(
                           constraints: const BoxConstraints(
-                            maxWidth: 5e2,
+                            maxWidth: double.infinity,
                           ),
                           child: Column(
                             children: [
@@ -167,25 +167,33 @@ class MathKeyboard extends StatelessWidget {
                                 padding: const EdgeInsets.only(
                                   top: 4,
                                 ),
-                                child: _Buttons(
-                                  controller: controller,
-                                  page1: type == MathKeyboardType.numberOnly
-                                      ? numberKeyboard
-                                      : type ==
-                                              MathKeyboardType.coachOnKeyboard1
-                                          ? standardKeyboard
-                                          : standardKeyboard,
-                                  page2: type == MathKeyboardType.numberOnly
-                                      ? null
-                                      : type ==
-                                              MathKeyboardType.coachOnKeyboard1
-                                          ? coachOnKeyboard1
-                                          : functionKeyboard,
-                                  onSubmit: onSubmit,
-                                  buttonColor: buttonColor,
-                                  highlightColor: highlightColor,
-                                  iconColor: iconColor,
-                                  submitColor: submitColor,
+                                child: Row(
+                                  children: [
+                                    Flexible(
+                                      child: _Buttons(
+                                        controller: controller,
+                                        page1: functionKeyboard,
+                                        page2: functionKeyboard,
+                                        onSubmit: onSubmit,
+                                        buttonColor: buttonColor,
+                                        highlightColor: highlightColor,
+                                        iconColor: iconColor,
+                                        submitColor: submitColor,
+                                      ),
+                                    ),
+                                    Flexible(
+                                      child: _Buttons(
+                                                                        controller: controller,
+                                                                        page1: standardKeyboard,
+                                                                        page2: coachOnKeyboard1,
+                                                                        onSubmit: onSubmit,
+                                                                        buttonColor: buttonColor,
+                                                                        highlightColor: highlightColor,
+                                                                        iconColor: iconColor,
+                                                                        submitColor: submitColor,
+                                                                      ),
+                                    ),
+                                  ],
                                 ),
                               ),
                             ],
diff --git a/math_keyboard_demo/lib/widgets/editable_mixed_text_field.dart b/math_keyboard_demo/lib/widgets/editable_mixed_text_field.dart
index 5377d59..cc6d739 100644
--- a/math_keyboard_demo/lib/widgets/editable_mixed_text_field.dart
+++ b/math_keyboard_demo/lib/widgets/editable_mixed_text_field.dart
@@ -230,7 +230,7 @@ String rightSide = '';
                             focusNode: mathFocusNode,
                             autofocus: true,
                               controller: mathController,
-                              variables: const ['x', 'y', 'z', '='],
+                              variables: const ['a', 'b', 'c', 'x', 'y', 'z', '='],
                               decoration: InputDecoration(
                                 border: OutlineInputBorder(),
                                 labelText: '수식을 입력하세요',