A hands on teaching aid which helps pupils understand addition, subtraction, multiplication and division.
Does not give you the answer, but tells you if you are correct via a balanced seesaw.
Also helpful in science, understanding leverage, fulcrums, moments and gravity.
Fun and interactive.
http://www.gyrobot.co.uk
http://www.facebook.com/gyrobotuk

Print without support and scale as large as you can.
I printed 20 red counters, you can print as many as you want, best to make the counters solid infill too so they have more of an effect on the beam.
Example:
Q. How many 7's in 28?
A. Put counters totalling 28 on one side (good for addition) and find out how many counters you need to put on the other side's 7 peg to make the seesaw balance.