Using Paired Books to Explore Math Concepts: Doubling

As a once-upon-a-time English education major, I'm intrigued with the idea of using paired books to explore math as explained in New Visions for Linking Literature and Mathematics. When I say "paired books," I'm thinking of books that could be compared and contrasted to consider any number of concepts--character, setting, plot...and, yes, math!

With that in mind, I read my son One Grain of Rice and The King's Chessboard, two books which tell stories of a rich royalty figure who, feeling indebted to a commoner (a poor village girl, a wiseman), agrees to pay the "paltry sum" of a single grain of rice...to be doubled each day for a period of days (a month, the squares on a chessboard.)

After reading the two books, we discussed ways in which they are similar and different. While the discussion alone was valuable, this time I also had my son record comparisons in a "Flip Flap with 3 Flaps book" (link gives you a basic template), with things unique to each book recorded under the left and right flaps and things that they hold in common recorded under the center flap, labeled "Both."

While we discussed a variety of topics, I'll highlight some of the math:

• For my 8yo, the obvious: "both think that the amount will be small but it's big."
• Measurement: we considered how the rice is measured in each book. In One Grain of Rice, it appears that the grains are literally counted out although the book never specifies how. In The King's Chessboard, the Weigher decides on day 12 that 2,048 grains of rice is equal to an ounce; from that day on, he continues with weight...ounces to pounds to tons.
• I asked my son to consider which character actually received the most rice, the village girl who received rice for a month or the wiseman who was to receive rice for each square of a chessboard but stopped early when the chessboard was only half filled.

Tricia left a comment noting that this folktale is also told in The Rajah's Rice. (On my Amazon list it goes!) You might also compared these books with other doubling stories: Two of Everything, The 512 Ants on Sullivan Street.

Are you interested in learning about more paired book options for math?

Tomorrow I'll share another math lesson based on these two books.