Mathematical reasoning has become a central task for evaluating and tuning reasoning Large Language Models (LLMs), yet existing benchmarks remain heavily biased toward high-resource languages, with English and Chinese dominating both pre-training corpora and evaluation suites. The recently released PolyMath (Wang et al., 2025) dataset represents a significant step forward, yet its coverage is still limited to 18 only high-resource languages. To address this gap, we introduce PluraMath, an extension of PolyMath to 18 additional {underrepresented languages spanning 6 language families -- ranging from mid-resource to extreme low-resource settings. We constructed the dataset through a human-curated pipeline, where native speakers thoroughly validated pre-computed translations. Using PluraMath, we then benchmark 27 reasoning LLMs across four model scales -- small, mid-size, large, and closed-source ensembles -- probing the multilingual mathematical reasoning capabilities of state-of-the-art models under diverse linguistic conditions. Our fine-grained analysis confirms a persistent gap in mathematical reasoning performance between high-resource and underrepresented languages, with stronger results largely associated with better instruction-following ability. We fully open-source our dataset, data acquisition pipeline, and evaluation framework, with the goal of lowering the barrier to multilingual benchmark development for underrepresented communities.
Alex: Welcome to another episode of ResearchPod. Today, we're discussing PLURAMATH, a new dataset designed to test how well AI models handle mathematical reasoning across many different languages.
Sam: So, this paper is basically asking whether AI models are actually good at math, or whether they're just good at math in English?
Alex: Exactly. The study explores whether mathematical reasoning is a universal skill or just a side effect of the fact that most AI training data is in English. And that distinction matters more than it might seem at first.
Sam: Right, because if we only test AI in a handful of languages, we're essentially ignoring most of the world's population. How did the researchers try to address that?
Alex: They built a new testing benchmark covering 18 underrepresented languages. The key feature was what they call a "human-in-the-loop" approach. Rather than just running problems through a translation program and calling it done, they had native speakers with advanced degrees in mathematics or computer science manually check every single translated problem.
Sam: That sounds like an enormous amount of work. Why couldn't they just trust the computer translations?
Alex: Because math isn't just words. It relies on a special formatting system called LaTeX—think of it as a kind of code that tells a computer how to display things like fractions, exponents, or square roots. When a general translation program processes a math problem, it often garbles that code. The symbols get scrambled, the structure breaks down, and suddenly the AI is staring at something that looks like nonsense, even if it could have solved the original problem just fine.
Sam: Oh, so it's not about translating the language of the question—it's about keeping the mathematical structure intact so the AI can actually read what it's being asked.
Alex: Exactly. And on top of that, the human experts also checked whether the mathematical terminology made sense within that specific language and culture. A term that translates cleanly from English into French might not have a direct equivalent in a less widely spoken language, and if the meaning shifts, the problem itself changes.
Sam: So once they had all this carefully verified data, what did they actually find when they put the AI models to the test?
Alex: They found a consistent gap. Models performed noticeably better when working in high-resource languages—English being the clearest example—than when working in the underrepresented languages, and this held true even after the translations had been carefully cleaned up. So the problem wasn't just messy data.
Sam: That's the interesting part to me. If the translations were verified and accurate, why were the models still struggling?
Alex: That's exactly what the study digs into. You might assume the issue is translation quality—that the AI is tripping over unfamiliar words or awkward phrasing. But the evidence points somewhere else. The researchers found that how well a model performs in a given language is only weakly connected to how well it can translate text in that language. What it's much more strongly connected to is something called general instruction-following ability—how well the model understands and responds to directions overall.
Sam: So it's less like the model is confused by the foreign words, and more like... it loses its footing when the instructions aren't in the language it was primarily trained on?
Alex: That's a good way to put it. Think of it like this: imagine you're a strong chess player, but you learned all the rules and strategies from a coach who only ever spoke to you in English. If someone suddenly gives you instructions mid-game in a language you barely know, you might still remember how the pieces move—but you'd struggle to follow the game plan. The underlying skill is there, but accessing it becomes harder when the instructions don't match your primary training.
Sam: That's a meaningful distinction. It suggests that just translating more training data isn't necessarily the whole solution—the models need to learn to follow instructions fluently across languages, not just recognize words in them.
Alex: That's what the study implies, yes. And it points to a real challenge for making AI tools genuinely useful on a global scale. The researchers also note that for languages with extremely limited written resources online, even this approach has limits—fully manual translation would be required, which is significantly more costly and time-consuming.
Sam: And I imagine there's also a question of whether the math problems themselves are equally relevant across different educational systems and cultures.
Alex: The study raises exactly that concern. Mathematical curricula aren't identical around the world, and a problem that feels standard in one context might be unfamiliar or framed differently in another. The researchers acknowledge this as an open question.
Sam: So PLURAMATH is less a final answer and more a careful first step—a way of making the problem visible so it can actually be addressed.
Alex: That's a fair characterisation. By building a verified, multilingual benchmark, the study gives researchers a clearer picture of where these gaps exist and what's actually driving them. That kind of diagnostic work is necessary before meaningful improvements can be made. Thanks for listening to ResearchPod.