Using a narrative non-fiction style with eye-catching illustrations of a haunted house and its occupants the author presents a beginners guide to algebra.

Starting with simple equations Billy and Mandy, with the help of bats, owls, ravens, cats, and skeletons, learn to find the mystery or unknown number using their addition, subtraction, multiplication, and division skills. The book finishes with a project to make a balance scale demonstrating the principles of an equation.

Here is a simple, delightful introduction that will encourage children to understand that solving mysteries can be fun, and algebra can help you solve math mysteries.

image by Evelyn Saenz 
 

review by Karen