Sometimes the best way to understand something is to see a model, especially for something as complex as the human heart. Looking at a model of the human heart will solidify an understanding of what the heart looks like in a child's mind. There are free-standing models of the human heart and heart models that fit with other organs. Three-dimensional models will often come on a stand for easier viewing. They are larger and students can see what the heart looks like in more detail. Many come apart so it is easy to see what is inside the heart. Full body models show children where the heart fits in with the body as a whole.
There are also reading materials and handouts to help children learn about the heart. The Franklin Institute has a comprehensive section on its website covering several topics about the heart. The website goes over how the heart develops, vessels, what the heart looks like, how it is monitored and tips for heart health. It also covers facts about blood and the history of heart disease. There are also children's books that explain how the heart works. One example is "Why Does my Heart Pump?: All About the Human Body," which covers the whole body in addition to the heart; it is a good way for children to understand how all the parts of the body fit in with the heart.
There are also a number of interactive online resources that children can use to explore the heart. For example, The Minneapolis Heart Institute Foundation has a lesson about the heart in their kid's corner called "Let's Learn About Your Heart!" Children are guided among a series of pages with animated pictures describing facts about the heart. Clicking on a Valentine's Day heart reveals a real picture of a heart, and users guide their mouse over the picture of a person to find the heart, which pops up once the user scrolls over it.
Movies can help kids learn about the heart while still keeping them entertained. For example, "The Magic School Bus" looks at the circulatory system in "Inside Ralphie." Standard Deviants looks at the heart as well in "Anatomy: The Circulatory System." This series was produced by college professors in an effort to entertain and educate. "Circulatory System" by Educational Video Network Inc. provides a more straightforward approach. This video was an Aegis Award Finalist, which is a general award set for video and film production.