diff --git a/calculator.h b/calculator.h
new file mode 100644
index 0000000000000000000000000000000000000000..10f3fe2f7823ea8dbbf587555f11af37d6a23102
--- /dev/null
+++ b/calculator.h
@@ -0,0 +1,59 @@
+#ifndef CALCULATOR_H
+#define CALCULATOR_H
+
+#include <QWidget>
+#include <QStack>
+#include<QLayout>
+class QLCDNumber;
+class QPushButton;
+class QGridLayout;
+class QRadioButton;
+class QHBoxLayout;
+
+class Calculator : public QWidget
+{
+    Q_OBJECT
+
+public:
+    Calculator(QWidget *parent = nullptr);
+    ~Calculator();
+    void calc();
+
+private:
+    void createOrdinaryCalculatorWidget();
+    void createSciExtrCalculatorWidget();
+
+    QLCDNumber* f_lcdNum;
+    QRadioButton* f_radioBtnCasual;
+    QRadioButton* f_radioBtnSci;
+
+    QStack<QString> f_operStack;
+    QString f_currentNum;
+    bool f_if_currNumChangable;
+
+    QPushButton* ce;
+    QGridLayout* f_BtnLayoutCasual;
+    QGridLayout* f_BtnLayoutSciExtr;
+    QWidget* f_BtnLayoutSciExtrWidget;
+    QWidget* f_BtnLayoutCasualExtrWidget;
+
+    QHBoxLayout* f_HBoxBtnLayout;
+
+    QGridLayout* MainLayout;
+
+
+    const double PI = 3.1415926535;
+    const QVector<QString> NumND = {"e", "pi"};
+    const QVector<QString> UnOp = {"rev", "sqr", "sqrt", "-x", "sin", "cos", "tan", "tanh", "sinh", "cosh", "ln", "exp", "n!", "cubic root", "cubic sqr"};
+    const QVector<QString> OpToCountimmediately = {"log", "ysqr", "ysqrt"};
+    const QVector<QString> SumOp = {"+", "-"};
+
+    QPushButton* createButton(const QString &p_str, size_t p_horz, size_t p_vert);
+
+public slots:
+    void slotButtonClicked();
+    void slotHideSci(bool);
+    void slotShowSci(bool);
+
+};
+#endif // CALCULATOR_H