By Kikkerland

Reviewed for Fifth Grade, 2011

Hydro Power Calculator

Can math help come in the form of...root beer? It can now, thanks to this cool new calculator. Just fill up the three water-powered batteries with a liquid of your choice, and you’re ready for Pre-Algebra. Not only is it eco-friendly by providing “free energy”, but the science behind it is pretty neat, too: moisture activates the carbon particles and produces energy. Clear plastic over the system board allows your child to see the science taking place! (Kikkerland, $10.95)