When you're implementing a user interface, you typically have some "design" or model of how it should work in your head. The main challenge is translating this intuitive model into a formal model that the computer can interpret for you. Math can definitely help you with this!

I think we should be emphasizing mathematical knowledge in front-end design and implementation, not trying to hide it under the covers. The better you are at math, the easier it is for you to implement the correct system for the design you want, and the less you have to compromise the design to fit the systems you have at hand.