ALA Booklist (Sat Oct 01 00:00:00 CDT 2011)

Although it's not unusual for a math book to explain equations and how to solve them, it is unusual when the setting is a haunted house on a moonlit night. First, this picture book introduces the idea that an equation is like a seesaw with one side balancing the other and the notion of a variable, "X," as a mystery that can be solved. After demonstrating a few equations with easy, guessable solutions, the text begins a narrative about Mandy and Billy, two children who have been in the illustrations from the start. They visit a haunted house, where caretaker Igor (and the household cats, bats, and skeletons) demonstrate how to solve equations using addition, subtraction, multiplication, and division. The story and lessons move along at a steady pace, while the eerie yet cheerful digital pictures illustrate the spooky setting, weirdly appealing characters, and even word problems with verve and style. An equation-related activity rounds out this kid-friendly introduction to basic algebra.

Horn Book (Sun Apr 01 00:00:00 CDT 2012)

Children are introduced to algebra through a haunted house full of mysteries. Spooky word problems demonstrate how addition, subtraction, multiplication, and division are used to solve simple algebraic equations. Halloween-themed illustrations punch up the subject's fun factor. A create-your-own balance scale activity is included.

School Library Journal (Thu Sep 01 00:00:00 CDT 2011)

Gr 3-6 Adler uses a mystery conceit to introduce algebraic equations and problem solving. Collaborating again with Miller, and using a Halloween theme, he employs the concept of a "mystery number" or variable that creates balance in an equation, showing how those numbers will be represented by letters. He begins very simply with illustrated examples of equations that many readers will be able to do in their heads. Once the concept is established, he continues with problems that require addition, subtraction, multiplication, or division in order to solve the "mystery," or equation. Each of the problems is posed in the form of a dilemma for characters Mandy and Billy, reinforcing that there are real-world applications for the skill. Adler sometimes uses the initial letter of the represented object in naming the variables ("K" stands in for "kittens," and "R" for "ravens"), but does not use this effective connection consistently. Miller's trademark wit and collagelike digital illustrations guide readers with visual references to the problem. The white font on dark pages is easy to read. The use of pumpkins and other Halloween icons may create too tight a niche for this title, and differences among elementary math programs may affect its usefulness, but overall Mystery Math presents the concepts with humor and clarity. Lisa Egly Lehmuller, St. Patrick's Catholic School, Charlotte, NC

Kirkus Reviews

Adler and Miller have once again turned out a thorough explanation of a math concept in a neat package (Fractions, Decimals, and Percents, 2010, etc.). This time they tackle the much-feared topic of algebra, starting with the basics and working up from there. Throughout, Adler introduces and then consistently uses mathematical vocabulary. He begins with a balanced seesaw as a simile for an algebraic equation, then leads readers from simple equations (4 + X = 5) that they can solve just by looking at equations in which they have to perform each of the four orders of operation. Easy-to-understand mathematical notations guide readers through the solution to each problem, which are originally posed as word problems involving two children, Mandy and Billy, and Igor, the caretaker of a haunted house. The Halloween theme echoes the idea of algebra as the solving of mathematical mysteries, and Miller's digital artwork ups the ante with a palette strong on blacks, dark blues and lime greens. Bats, black cats and skeletons abound, and Igor himself has green skin à la Frankenstein's monster. Backmatter includes instructions on making a balance scale and weights from common household materials. A solid foundation for beginners or re-teaching tool for those who are struggling. (Math picture book. 6-10)

Publishers Weekly (Fri Oct 06 00:00:00 CDT 2023)

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-for 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 6-10. (Aug.)