A coordinate system is a set of one, two, three or more coordinate axes. An axis and a unit segment form a coordinate axis. These axes cross in the point of origin. A coordinate system with perpendicular axes is called a perpendicular coordinate system. If such system has the same unit segment for each of the axes then it is called Cartesian coordinate system. An axis OX is called the abscissa axis, an axis OY is called the ordinate axis. The model is a shooting game. You have a target (a battleship on the coordinate grid). Set its coordinate (x and y) and click the Fire button. A missile is launched from the point of origin to the reference point. If you hit the battleship then it will take fire and a score will increase. The next target of 12 appeares. A statistics of your shots is shown as 12 pictures. A picture with a battleship corresponds to a future target, a burning ship shows a destroyed target. A picture without ship is a missed target. A sandglass is appeared if your time for a shot has expired. You can select a level of the game. There are Newbie, Advanced and Professional. The Newbie has no time limit. At the Professional level a coordinate system is changed from shot to shot. At the Demonstration mode you can`t change the coordinates, but if you press the Fire button they would be shown on the radar. The Reset button returns you to the mode and level choosing.
