This type of development is really cool and fifth graders especially will like it too as you can incorporate some of the stuff they like to do right now into your presentation.
As you know, motor tasks require either static balance, dynamic balance, or some combination of both.
If you know any gynmastic moves, you can make up a lesson such as headstands, handstands and high beams - balance bars. Their balance should be developed by now so most of them won't have any truble doing those.
Here are some other examples. For static you could do the following: holding the body in one position, standing on one foot, statue game, freeze tag, standing with a bean bag on their heads, balancing on a body ball
Examples of dynamic: walking forward on a tape on the floor, walking on a balance beam, log roll, forward roll, jumping in the air, action ball, soccer and climbing.
You can also go online and do a search on each and they will provide you with some lessons.
Hope this helps and good luck.