Mystery Math: A First Book of Algebra

In an entertaining and effective math primer, two children solve a haunted house's riddles using algebra. "The two sides of each equation are balanced. They're equal," Adler explains, before introducing the concept of a variable or "mystery number." Igor, the green-faced caretaker, poses word problems that can be solved using algebraic equations%E2%80%94for example, if Igor saw bats flying around earlier, saw 12 more fly in, and there are 27 bats now, how many were in the house before? For readers who normally run screaming at the mention of math, Adler's clear explanations and Miller's lightly spooky digital cartoons should prove reassuring. Ages 6%E2%80%9310. (Aug.)