Is it didactic, a story built specifically to teach a lesson about fractions? Absolutely.
Do some of us prefer our mathematics lessons encased in a story? Yes, indeed.
Just a spoonful of sugar helps the medicine go down. And for some people, math equals medicine.
The Sir Cumference books are designed to engage young readers who like knights and ladies fairs and castles and to teach them a bit of math on the sly, so to speak. This latest Sir Cumference book is all about fractions. Sir Cumference and Lady Di of Ameter go to visit their friend the Earl of Fracton at the annual Fracton Faire. At the fair, they purchase cloth and cheese and other stuff in fractional parts, and a group of thieves target the market. However, the Earl and Lady Di and Sir Cumference use fractions to catch the bandits.
The ending is a bit lame. (The thieves get away, but the loot they took from the merchants at the fair is recovered.) Everyone lives happily ever after, and fractons later become known as fractions. Nevertheless, this story would be a memorable and gentle introduction to or review of the subject of simple fractions.
Other Sir Cumference books are:
Sir Cumference and All the King’s Tens (in my library)
Sir Cumference and the First Round Table (in my library)
Sir Cumference and the Roundabout Battle
Sir Cumference and the Viking’s Map
Sir Cumference and the Dragon of Pi
Sir Cumference and the Isle of Immeter
Sir Cumference and the Great Knight of Angleland
Sir Cumference and the Sword in the Cone
Sir Cumference and the Off-the-Charts Dessert
Another “living math” picture book that I picked up at the used bookstore is The Greedy Triangle by Marilyn Burns. (Ms. Burns wrote two of the books in the Brown Paper School series, Math for Smarty Pants and The I Hate Mathematics Book!, and her name is on a series of math education books from Scholastic for preschool and primary readers, Marilyn Burns brainy day books.) The Greedy Triangle is about a triangle with a busy life who nevertheless becomes bored with doing the same old triangular things. With the help of a shapeshifter, our triangle tries out life as a quadrilateral, a pentagon, and a hexagon, then several other shapes all the way up to a decagon. But, of course, then the old life of a triangle starts to look good, and our shape-shifting shape asks for one last change.
I think this kind of “didacticism” is a just fine. Stories make math so much more interesting. Then again, I was usually the only one in my math classes who actually liked story problems best. Unadorned numbers make me cringe.