If you have five grasshoppers and each of them has two wings, how many wings are there total? Not only do insects themselves multiply but they can be used to help reinforce multiplication facts for children. Other insects featured in the book include fireflies, luna moths, dragonflies, ants, honeybees, ladybugs, walking sticks, monarch butterflies, and spittlebugs. Do you know what pirate bugs are and what they eat? And if each pirate bug eats eight of its prey, how many pests will be gone? As the author says, "Numbers are an important part of our world. You can find them in school, sports, and nature. When you know how to multiply numbers, you can figure out almost anything!" The rhyming text by author Suzanne Slade, who has written over eighty books for children, emphasizes both various multiplication facts and bits of information about each insect, while the close-up sketches by Erin Hunter, who specializes in entomological and botanical illustration, will enable youngsters to know what the different insects look like. Additional material on insect body parts and life cycles, along with matching and compare/contrast activities, plus two further pages about multiplication may be located in the "For Creative Minds" section at the back. Also more free activities for parents and teachers to with use the book can be found online at the publisher's website. The age range is given as four to nine. One might use Multiply on the Fly to introduce the concept of multiplication to pre-schoolers and first graders, but I personally doubt if it will make much sense until at least second or maybe third grade. However, it is cute and well-done.