I am developing an android app, A Calculator. 
I have used double to save the operands. 
As a calculator calculates bigger number, it's not showing the answer properly.
For Example, If I enters 1234567890 \* 1, it shows me the result 1234567936.
I think it is due to the range issues of double.
How to solve it? Help!

This is a part of the actual code containing operator's functioning:

```
bAdd.setOnClickListener(new View.OnClickListener() { // Add Button
                                                                // Listener

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                try {
                    if (Switch == true) {
                        display.setText(display.getText() + "");
                        op1 += Float.valueOf(display.getText().toString());
                        check = 'a';
                        display.setText(" ");
                        display2.setText("+");
                    } else if (display.getText().toString() != " "
                            && Switch == false) {
                        display.setText(display.getText() + "");
                        op1 = Float.valueOf(display.getText().toString());
                        check = 'a';
                        Switch = true;
                        display.setText(" ");
                        display2.setText("+");
                    } else {
                        throw new Exception();
                    }
                } catch (Exception e) {
                    display.setText(" ");
                }

            }
        });
        bSub.setOnClickListener(new View.OnClickListener() { // Subtract
                                                                // Button
                                                                // Listener

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                try {
                    if (Switch == true) {
                        display.setText(display.getText() + "");
                        op1 -= Float.valueOf(display.getText().toString());
                        check = 's';
                        display.setText(" ");
                        display2.setText("-");
                    } else if (display.getText().toString() != " "
                            && Switch == false) {
                        display.setText(display.getText() + "");
                        op1 = Float.valueOf(display.getText().toString());
                        check = 's';
                        Switch = true;
                        display.setText(" ");
                        display2.setText("-");
                    } else {
                        throw new Exception();
                    }
                } catch (Exception e) {
                    display.setText(" ");
                }

            }
        });
        bMul.setOnClickListener(new View.OnClickListener() { // Multiply
                                                                // Button
                                                                // Listener

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                try {
                    if (Switch == true) {
                        display.setText(display.getText() + "");
                        op1 *= Float.valueOf(display.getText().toString());
                        check = 'm';
                        display.setText(" ");
                        display2.setText("x");
                    } else if (display.getText().toString() != " "
                            && Switch == false) {
                        display.setText(display.getText() + "");
                        op1 = Float.valueOf(display.getText().toString());
                        check = 'm';
                        Switch = true;
                        display.setText(" ");
                        display2.setText("x");
                    } else {
                        throw new Exception();
                    }
                } catch (Exception e) {
                    display.setText(" ");
                }

            }
        });
        bDiv.setOnClickListener(new View.OnClickListener() { // Divide
                                                                // Button
                                                                // Listener

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                try {
                    if (Switch == true) {
                        display.setText(display.getText() + "");
                        op1 /= Float.valueOf(display.getText().toString());
                        check = 'd';
                        display.setText(" ");
                        display2.setText("/");
                    } else if (display.getText().toString() != " "
                            && Switch == false) {
                        display.setText(display.getText() + "");
                        op1 = Float.valueOf(display.getText().toString());
                        check = 'd';
                        Switch = true;
                        display.setText(" ");
                        display2.setText("/");
                    } else {
                        throw new Exception();
                    }
                } catch (Exception e) {
                    display.setText(" ");
                }

            }
        });

```

This a part of actual code containing equal's to functioning:

```
bEq.setOnClickListener(new View.OnClickListener() { // Equals To
                                                            // Button
                                                            // Listener

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                try {
                    if (display.getText().toString() != " ") {
                        double result;
                        int temp = 0;
                        op2 = Float.valueOf(display.getText().toString());
                        op1 = Math.floor(op1 * 100) / 100;
                        op2 = Math.floor(op2 * 100) / 100;
                        if (check == 'a') {
                            result = op1 + op2;
                            temp = (int) result;
                            if (result - temp == 0) {
                                display.setText(String.valueOf(temp));
                            } else {
                                display.setText(String.valueOf(result));
                            }
                        } else if (check == 's') {
                            result = op1 - op2;
                            temp = (int) result;
                            if (result - temp == 0) {
                                display.setText(String.valueOf(temp));
                            } else {
                                display.setText(String.valueOf(result));
                            }
                        } else if (check == 'm') {
                            result = op1 * op2;
                            temp = (int) result;
                            if (result - temp == 0) {
                                display.setText(String.valueOf(temp));
                            } else {
                                display.setText(String.valueOf(result));
                            }
                        } else if (check == 'd') {
                            if (op2 != 0) {
                                result = op1 / op2;
                                temp = (int) result;
                                if (result - temp == 0) {
                                    display.setText(String.valueOf(temp));
                                } else {
                                    display.setText(String.valueOf(result));
                                }
                            } else {
                                display.setText(" ");
                                display2.setText("Invalid");
                            }
                        } else if (check == 'p') {

                            try {
                                if (op2 == 0) {
                                    throw new Exception();
                                } else {
                                    result = (op1 / op2) * 100;
                                    temp = (int) result;
                                    if (result - temp == 0) {
                                        display.setText(String
                                                .valueOf(temp) + "%");
                                    } else {
                                        display.setText(String
                                                .valueOf(result) + "%");
                                    }
                                }
                            } catch (Exception e) {
                                display.setText(" ");
                                display2.setText("Invalid");
                            }

                        }
                    } else {
                        display.setText(" ");
                    }
                    Switch = false;
                    check = '\0';
                    display2.setText("=");
                } catch (Exception e) {
                    display.setText(" ");
                }

            }
        });
    } finally {
    }

}

```