On the subject of adding pennies for weight (which I actually suggested to my team on Sunday, half jokingly, but for decoration instead...):
1 penny = $.01 = 2.5 grams
1 Nickel = $.05 = 5.0 grams
1 Dime = $.10 = 2.268 grams
1 Quarter = $.25 = 11.340 grams
1 Pound = 453.592 grams.
This means to get 1 Pound of ballast weight using each common U.S. coin, you would need:
Pennies: 181.4368 = 182 = $1.82/lb
Nickels: 90.7184 = 91 = $4.55/lb
Dimes: 199.9964 = 200 = $20/lb
Quarters: 39.99929 = 40 = $10/lb
(Source:
http://www.usmint.gov/about_the_mint...specifications)
Therefore, the most economical coin to use as ballast would be pennies. But if you really want to show off, use Dimes!
Even more fun: You can probably get MOST of those pennies for free...have every student check under their couch!
Or, if you are really rolling in the dough, use the Presidential or Native American $1 coins, needing 56 to make just over a pound!