Read off the coordinates of the point symbolized by the red circle and insert them into the respective text fields. All coordinate values are integer or half-integer.
Click the button "Check" in order to see whether your values were correct. Click the button "Next" in order to try again with another point. You may also correct a false input, thereafter click again "Check". Repeat the exercise several times. In case you have inserted a wrong guess, repeat until more than 90 percent correct answers are displayed.