Online Practise with Ordered Pairs

Here is the link to an online game that helps you to practise ordered pairs on a Cartesian coordinate plane. 

There are also harder and easier options to practise even more of your skills with a grid. 

http://www.funbrain.com/cgi-bin/co.cgi?A1=s&A2=1

Here is another one in which you have to locate aliens on the grid. 

http://www.mathplayground.com/locate_aliens.html