Inequality Pacman

If you want to describe a point you use coordinates (2,5), for lines you use functions: y=-3x+2, but what about whole "regions"?

One way is to use "inequalities". An "inequal" function is one in which you define the y-coordinate as being "greater than: >", "greater than OR equal to: ", "less than: <", or "less than OR equal to:". There are many ways to remember which way round the sign should be, one of which is to draw a "pacman" around the symbol and remember, pacman always eats the BIGGEST portions.

Watch the video below for a quick overview of the gameplay, then scroll down and start lasering some ghosts!


  • Best played as a two player game.
  • You need to be comfortable with finding the equation of a line before trying this activity. If you are not, your teacher may direct you to try: Straight Line Graphs.
  • The ghosts have kidnapped your baby brother/sister. Modify the inequalities to reposition the "laser fields" so that they 'take out' each ghost in turn until they are all neutralised and the baby can escape.
  • Different ghosts exist within different energy fields. You can only eliminate ghosts with the laser that is the same colour frequency i.e. green lasers won't work on orange ghosts etc.
  • The inequality region needs to capture entirely the ghosts movement for the ghost to disappear, but be careful, if the inequality isn't precise enough they could burn the baby! After each life lost, it's your partners turn to try and free the baby.
  • A big smiling baby will appear and escape once all the ghosts have been eliminated.
  • As you progress through the levels the games get harder. In Level7 your lasers have misfunctioned and are burning the baby! You must quickly reset them, before changing their positions. To change the inequality you have to type in <= to get the less or equal than symbol and >= to get the greater or equal thansymbol.


Try each of the levels from 1 to 4 below. Levels increase in difficulty from one to three ghosts, but only using linear inequalities. See the video or description above if you are unsure what to do. 

Ready for a challenge? Try these harder levels 5 to 7 Pacman2 Inequalities

Pacman Inequality 1  Free the Babies . .

Pacman Inequality 2

Pacman Inequality 3

Pacman Inequality 4

All materials on this website are for the exclusive use of teachers and students at subscribing schools for the period of their subscription. Any unauthorised copying or posting of materials on other websites is an infringement of our copyright and could result in your account being blocked and legal action being taken against you.