Applications
Explanation
The Joke
The comic depicts two cavemen walking together in a prehistoric landscape. One of them declares: "Me only work in numbers above six. Is no applications." This is a joke about pure mathematics -- the caveman is essentially a prehistoric version of a pure mathematician who works only in abstract, "useless" mathematics and proudly declares that his work has no practical applications.
The caption below reads: "Early pure mathematicians." The humor comes from transplanting the age-old tension between pure and applied mathematics back to the Stone Age, where the numbers involved are hilariously small. A modern pure mathematician might work in abstract algebra or topology with no immediate real-world use; this caveman's version of the same intellectual snobbery is refusing to work with numbers six and below -- presumably the only numbers that a caveman would actually need for counting tools, animals, or family members.
The Humor
The comedy relies on anachronism and deflation. The attitude of the caveman perfectly mirrors the stereotype of modern pure mathematicians who take pride in the "uselessness" of their work, famously exemplified by G.H. Hardy's "A Mathematician's Apology." But reducing this grand intellectual tradition to a caveman who only works with numbers above six is delightfully absurd. The caveman's broken grammar ("Me only work," "Is no applications") adds to the charm, grounding the lofty attitude in the most primitive possible context. The joke also plays on the idea that "no applications" in the Stone Age is even more extreme than today -- when you can barely count to ten, refusing to use most of your numbers is spectacularly impractical.
References
This comic references the long-standing divide in mathematics between pure mathematics (pursued for its own sake) and applied mathematics (pursued for practical use). The phrase "no applications" echoes the famous pride some pure mathematicians take in their work having no practical utility, most notably G.H. Hardy, who wrote in "A Mathematician's Apology" (1940) that he had never done anything "useful." Ironically, Hardy's work in number theory later found critical applications in cryptography.