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It was admittedly a difficult book in some ways for all of my boys to get into, mainly because of the style of the language, but in the end, they all enjoyed it. We followed along with Jump Into a Book's pirate adventures, and we also came up with a few of our own. We set up the playmobil pirate ship and recreated the battle scenes from the story.
And much time was spent dressing up in pirate gear and staging stunt-man worthy sword fights and treasure hunts. We watched Pirates of the Carribean on dvd and discussed its similarities to Treasure Island. The old Disney version of Treasure Island is available on dvd, and we have it on our wish list.
I found some Treasure Island coloring books at Michael's for $1 apiece, and the boys enjoyed coloring in them while I read the chapters aloud each night. It also helped keep the squirms and wiggles from becoming a distraction and allowed everyone to listen and get involved in the story. They liked having pictures to accompany the story, too.
While I was at Michael's, I also found some wood craft kits that you paint and glue together to make these--
If you want to really go in-depth with a study of Treasure Island, check out this unit study chock full of kid-friendly activities and lessons.