Free science and math simulations for teaching STEM topics. Over 360 million simulations!
phET interactive simulations offers teachers and students over 360 million free simulations revolving around science and math topics for free. Simulations are available from elementary all the way to University.
If you join the site (free) you can share a topic directly into Google Classroom!
Embedded below is a 1 minute and 22 second example showing area model introduction.