As detailed here there was an intention to create resources that were compatible with IWBs and iPads.  Unfortunately as detailed here technology is not at the point where this can be done at the moment.  As such this resource is aimed directly at the iPad.  It should work on Internet Explorer 9, Safari and Firefox 7 but there are so many differing possible set ups that they can’t be guaranteed.  This resource is largely a copy of the Difference Triangle Resource but with different graphics to work in a lesson I teach where the puzzle is also shown using physical pool balls.

The challenge is to swap the pool balls until each ball is the absolute difference of the two below it.  Note the difference is always the larger number minus the smaller one.  Hence 5 and 3 have a difference of 2 as do 3 and 5.  A flashing ring around a ball indicates that it is not the correct absolute difference of the 2 below. The absence of a flashing ring shows that the difference is correct but it does not mean that the location of the ball is correct.  When all balls are placed correctly the player will be informed.

Obviously if you are able to use it with an iPad you can set it as a solo or small group challenge.  The resource can be saved to the iPad by selecting to save it to the home screen where it will perform as an app off the app store.

There is an article on how the similar Difference Triangle can be used in lessons on the supporting site to this teacherledplus.com.