Puzzle Hunt Game

It's getting difficult for games involving 4 years olds as well as 11 year olds.  What I do is grab a couple of puzzles we have around and scan a copy of it. (hard wooden 10 piece for younger children and 25 pieces for older kids).  I color the back of all the same puzzles pieces certain colors (red for the youngest, blue for the middle, and green for the older kids puzzle)and then hide them throughout the yard (FYI-keep track of where the pieces are so you don't misplace them for future use).  They're hidden before the kids get to the party.  When the kids are filtering in, they're taking pictures with a Polaroid and cutting them in "puzzle" pieces (mom's and dad's help the younger kids with the cutting part)then place them in zipper bags.  They then swap them with the other kids to put together (they don't tell each other what they are before putting them together-no prizes but keeps the kids busy).  When all the kids arrive, I break them into age appropriate teams and tell them what they are hunting for in the yard, showing them the picture.  They'll know it's the right piece by the color on the back. They're to leave the wrong color where they found it.  The younger kids use the scanned copy as a template for the puzzle while the other kids have to put it together by memory.  The first team to finish wins.