Difficulties with the calculator?

Using the calculator is very simple, you can use the left and right arrows to change the field and the numbers to fill them, with the up and down arrows, you can increase or decrease the values, besides, you you can type Delete to delete everything or Backspace to delete just a piece. Easy isn't it?!

When everything is ready, you can type Enter or the equal sign to see the result that will appear on your right just below the word History.