Wendy Lichtman's novel The Writing on the Wall is the most recent addition to my small collection of middle grade novels with a mathematical theme. It's a well-written school story where eighth-grader Tess's fascination with mathematics plays a key role.
Tess loves math, and she likes to make mathematical analogies for people and dilemmas in her everyday lift. For example, she calls her friend Sammy "s to the fifth" becasue Sammy inflates everything and often says things five times. Miranda is "the absolute value of m" because, like the absolute value of a number, Miranda is always positive.
The plot centers around a series of mathematical clues left as graffiti on the back wall of a church across from Tess's school. The clues seem to point to a crime, and they also seem to be aimed at Tess as the one person who can decipher them. Tess, who is being tormented by a boy named Richard and needs the distraction, finds herself drawn into the mystery to the degree that she ignores a strong warning from the principal and starts writing some graffiti of her own.
So on the one hand, this is a mystery story with codes and clues. On the other hand, it's the story of a usually obedient and responsible student drawn into careless delinquency becasue of her obsession with numbers and with being in control. Consequences follow, and Tess has to do some re-thinking of her own motivation.
A real strength of this story is that the characters, adults and kids alike, are well-drawn and believable. One of the best is Mr. Z, the snide computer teacher. Tess is an observant narrator, though not, as she realizes, an intuitive one. The math she presents in this book will be clear and accessible to students in grades 5-8, and it's well woven into the story.
This is the second book about Tess and math, so the earlier one, Secrets, Lies, and Algebra, is worth checking out, too.