activities:content:highlights:mvpchain

This small group activity using surfaces combines practice with the multivariable chain rule while emphasizing numerical representations of derivatives.
Students work in small groups to measure partial derivatives in both rectangular and polar coordinates, then verify their results using the chain rule.
The whole class wrap-up discussion emphasizes the relationship between a directional derivative in the $r$-direction and derivatives in $x$- and $y$-directions using the chain rule.