Differential Equations in Action
https://www.udacity.com/course/differential-equations-in-act...It's not an intense differential equations course, and I don't think you even need calculus to understand or complete the exercises. It has a lot of really great, well, explained, fun exercises like computing a gravitational slingshot, computing the spread of an epidemic, then N-body problem, and others. The exercises are solved programmatically, not with math equations.
America's Unwritten Constitution
https://www.coursera.org/learn/unwritten-constitution
America's Written Constitution
https://www.coursera.org/learn/written-constitution
If you're American, you'll likely find both of these courses extremely interesting. What they (probably) taught you in grade/high school was very overly simplified, or just wrong. This is geared toward people who have no background in law. I don't remember there being amazing exercises to do, but there were a lot of mind blowing facts I learned about things the constitution does and doesn't cover.