http://cellar.org/iotd.php?threadid=20604

and I'll raise

http://cellar.org/iotd.php?threadid=23711

For blueboy in D-Jim's link from 2009 ... better late than never

I have a few wheat pennies. I love wheat pennies and separate them whenever I see one. But not nearly enough for a cool project like that! Then again, you kind of want to see the front and back of wheat pennies.

V, I was trying to be facetious... :rolleyes:

I agree a single circle packs very efficiently in a single hexagon.
But unless the floor is a hexagon of exactly the right size for US pennies,
the problem changes to one of optimal packing hexagons.

I assumed a regular shape of a rectangle or square.

Erich's packing center
Packing Equal Copies
Attachment 39268

Unit circles in a square
Attachment 39270

Unit circles in a hexagon
Attachment 39269

So without changing the size and/or shape of the floor to accomodate the US penny,
the optimal packing pattern may more difficult/impossible to find.

You are going to be right against two walls and within the diameter of a penny from the other two. Thats what trim is for.
So back to my original question how many pennies fit in a 12"x12" space?

Technically, I think you have changed the problem, but...
The simplest pattern to visualize is this:

Attachment 39274

If pennies are 0.75 inches in diameter, this pattern would hold 16 per linear foot.
16 x 16 = 256, or $2.56/sq ft.

But the pattern used in the OP was different, and more efficient.
So if you change the pattern towards a more "optimum" packing,
(or towards maximum number that will fit in a square foot)
the number or cost, obviously, would be higher.

The difficulty in calculating the optimum packing comes in selecting repeating "tiles" that fit the specific area efficiently.
Just as BigV said earlier. Circles fit hexagons very efficiently, but hexagons don't fit squares efficiently at the edges.

so the figure I read was relatively accurate. thanks.
I believe that amount would give one a good idea of the cost to cover their floor
... within a few pennies anyway.

From mah link up thar. Don't know how it's relevant or not relevant 'cause I barely read a damn word any of ya said about cost and pennies per square foot. :lol:

lol - thats what made me post my original question. :p:
I think that number actually refers to the TOTAL cost per sq ft, but was written incorrectly.

Hmm...a little like my husband, I suppose lol...I wish he was make me a floor like that!

:)
Actually now that I saw some more pics of him on FB - not as much as I thought. :/