When Arithmetic Breaks The Universe

When basic subtraction turns into existential crisis! The teacher starts with a simple fraction problem (5/12 - 6/12), which should equal -1/12. But then the class troublemaker busts out an infinite series sign, and suddenly that innocent little negative fraction becomes infinity.

This is actually a mathematical inside joke about how certain divergent series in advanced mathematics can yield bizarre results. Some infinite series manipulations can make it look like -1/12 equals infinity (or technically, that the sum of all positive integers equals -1/12). It's the kind of math that makes even calculators throw themselves out windows.

The teacher's expression in that last panel is every mathematician who's had their comfortable world of elementary arithmetic shattered by the chaos of higher math. Welcome to the point where numbers stop making sense!