Equation Calculator

When you have used a calculator, have you ever thought of these things below ?
- want to take notes about calculation
- want to leave the equation about calculation

This is a Simple Calculator App.
You can use an Expression. It's automatically calculated.
The four basic arithmetic operations and Parentheses are supported.

You can input multiple lines when you write an equation.
You can save the equation and Answer. You can see the saved-data in the calculate-history window, to which you can add a memo.

When the cursor is at the position of Parenthesis, the pair of Parentheses will be highlighted.