**New book: You Can Count on Monsters, by Richard Evan Schwartz *91 **(A K Peters)

**The author:** About seven years ago, Schwartz made a simple book of black-and-white drawings of monsters — each one associated with a number — for his precocious daughter, then five, to help her learn about prime and composite numbers and factoring. A couple years later, he expanded the concept, eventually covering numbers 1 to 100 and making a poster of the fun monsters. “The National Science Foundation (main division) liked it so much that they have a giant one hanging in their office,” he said. Last year, he turned the poster into a colorful book.

Math has been like a “constant companion” to Schwartz, today a mathematics professor at Brown University and a Guggenheim Fellow in 2003. One reason he likes math, he said, is “the fact that there is (usually) a way to decide if a mathematical statement or argument is true. So talking about math is much more productive for me that talking about lots of other subjects, like politics.”

**The book:** Intended for elementary-age children, *You Can Count on Monsters* first explains the basic ideas of multiplication, prime and composite numbers, and factoring. Then for each number, from one through 100, the book’s left-hand pages depict the number broken down into its prime factors using dots and factor trees, and on the facing page, there is a playful monster that relates to the number.

The monsters are designed to help children understand the building blocks of numbers. Each prime number is represented by a different monster. For example, the monster for the prime number 2 has two big eyes. For each composite number, the scene depicted involves the monsters for its prime factors. So the number 14, for instance, involves a scene with the monsters for the prime numbers 2 and 7. Young readers can have fun figuring out how the monster is related to its prime numbers.

**A page from the book: **The monster for 14 (2×7) includes the monster for the prime number 2 and the monster for the prime number 7. Can you identify them?

*By Katherine Federici Greenwood*

**Read about more Princeton authors on The Weekly Blog and view a complete list of works by alumni, faculty, and students at PAW online.**

mutuelle pas cherthank u bro.

hahahaha

judsjo

seasleyI have the same Question?

Jill HI would love to get copies of the original poster. Are they available anywhere?

Mutuellethis picture above makes me remember the carton ” les zinzin de l’espace.