Sir Cumference and the Isle of Immeter is a book about how these two kids, Per and Radius, were taught to multiply. In this book, Per and Radius used their 'Inners and Edges' theory to unlock the secret to the Isle of Immeter and defeat the sea serpant. In the book Per uses her knowledge of how to determine the radius of a circle to determine the perimeter of a rectangle.

Personally, I was completely lost by what this book was saying. I have know idea how the kids found some of the stuff the way that they did and didn't understand their 'Inners and Edges' game. I think it was an interesting book but I most definitely was confused by how they were trying to teach this through the use of this story.

A classroom extension I would use would be to have the class to take and orange and make it into a rectangle and then measure it the way Per did to find the perimeter and then we would measure to see what the actual perimeter was to see if this method really works. Another I would use would be to show how when you lots of items in rows and columns to count how many rows and the count how many in each column to multiply to get the total of items without having to count each and every one.