Every elementary school classroom should have about $20 in change. Not fake money printed on a piece of paper, but real money. Yes, some of it will go missing over time, and you might need to lock it up depending on your community, but honestly it’s worth the risk. It’s only $20.
Like it or hate it, money is an integral part of our lives. If you want your students to understand the world, you have to provide them with the tools they need. Your students aren’t going to learn about how to add up change without holding it in their hands.