> Financial models, physics models, biology models commonly use them. In what specific everyday situations would most people find these useful? It's not like i

> Financial models, physics models, biology models commonly use them. In what specific everyday situations would most people find these useful? It's not like it's common for people run into situations where they say "if only I could calculate the predator prey systems" or "if only I could calculate radioactive decay." I've studied these, and I don't think I've ever run into some everyday situation where I've said "Man, I'm really glad I can apply my differential equations/vector calculus/etc. here." Even in the rare situation where I want to calculate compound interest I opt to just use a interest calculator since it's quicker and less error prone than doing it by hand.