One lesson a week for fifteen students felt like bailing the ocean with a cup
In the favelas and public schools of Rio de Janeiro, two seventeen-year-olds have quietly confronted one of education's oldest inequities: the student who has no one to ask. By building a mathematics tutoring bot that lives inside WhatsApp — requiring nothing more than a basic smartphone — Felipe Kaplan and Felipe Garcia have extended a hand across the digital divide to five thousand students, and are now looking toward Angola and Mozambique. It is a reminder that the tools of transformation sometimes arrive not from institutions, but from young people who simply refused to accept the limits of a cup when the ocean needed bailing.
- Weekly tutoring sessions in Rocinha reached only ten or fifteen students at a time — a scale so small it felt like a structural failure dressed as generosity.
- The solution had to live where students already were: WhatsApp, low on data, light on hardware, already open on millions of phones across Brazil.
- Five thousand users arrived within months, but growth exposed a flaw — the bot's silence in the face of profanity was not neutrality, it was negligence, and the code had to change.
- The two Felipes now face the harder questions: how to measure real learning gains, how to fund the infrastructure, and whether their creation belongs to the market or to the commons.
- Pilots in Rio's municipal schools and expansion into Portuguese-speaking Africa are on the horizon, carrying the quiet ambition of a local fix becoming a continental one.
A chicken-and-rabbit logic puzzle arrived via WhatsApp one afternoon — sent not by a tutor, but by Mister Pi, an AI chatbot built to teach mathematics to students who have no one to ask. The bot offered guidance without surrendering answers, prompting its user: "Don't forget to tell me your reasoning."
Behind it are two seventeen-year-olds from Escola Americana in Rio de Janeiro. Felipe Kaplan had already founded Conte Comigo in 2024, pairing his school's students with children in the Rocinha favela — but one session a week for a handful of students felt inadequate against the scale of the need. He turned to a format that could travel farther: a WhatsApp bot, requiring minimal device resources, reachable by anyone with a basic smartphone. The first version launched in April 2025, refined through testing with students from the Fundação Darcy Vargas and Conte Comigo participants. Felipe Garcia then joined to lead growth, working with influencers and school networks to spread the word.
Within months, Mister Pi had reached roughly five thousand users across public and private schools. Growth, however, surfaced new responsibilities. During an internship at Rio's municipal education department, Kaplan recognized that ignoring inappropriate messages wasn't enough — the bot needed to actively steer users toward better behavior, and the code was updated accordingly.
The project now stands at a crossroads. The two Felipes are working to build measurement tools that can track genuine student improvement, planning a pilot in Rio's municipal schools, and exploring expansion into Angola and Mozambique. Fundraising has begun to cover operational and AI costs, though the question of whether Mister Pi becomes a company or a nonprofit remains open. Both continue building either way — and the bot, for its part, keeps asking students to show their work.
A chicken-and-rabbit logic puzzle arrived in my WhatsApp one afternoon—twenty heads, fifty-six legs, how many of each?—sent by Mister Pi, a chatbot designed to answer math questions. I was preparing for a parent-child math olympiad with my eleven-year-old son, and the bot had generated a list of problems we might encounter. As we worked through them together, it offered guidance without simply handing over answers: "Don't forget to tell me your reasoning."
Mister Pi exists to solve a problem that looks simple on the surface but runs deep: how do you teach mathematics to students who have no one to ask? Two seventeen-year-old students at Escola Americana in Rio de Janeiro decided the answer was to build a WhatsApp bot powered by artificial intelligence. Felipe Kaplan, the creator, had already launched a tutoring initiative called Conte Comigo in 2024, pairing his school's students with children and teenagers in the Rocinha favela. But one lesson per week for ten or fifteen students felt like trying to bail out the ocean with a cup. He needed scale.
Kaplan began experimenting with remote teaching models and landed on the chatbot format—something that could live in WhatsApp like a regular contact, requiring minimal phone or computer resources, accessible to anyone with a basic smartphone. The first version launched in April 2025 and went through refinement with students from the Fundação Darcy Vargas, which offers free primary and secondary education courses, and with participants in Conte Comigo. When the model was solid, Felipe Garcia, also from Escola Americana, joined the project to handle promotion and user growth, working with influencers and other students to introduce the bot in schools.
Within months, Mister Pi had reached approximately five thousand users across public and private schools. But growth brought complications. During an internship at Rio's municipal education department earlier this year, Kaplan realized the bot's approach to handling inappropriate messages and profanity was insufficient—simply ignoring them wasn't enough. The system needed to guide users toward better behavior. That adjustment went into the code.
The two Felipes are now at a critical juncture. They need to refine their models to measure how students actually improve through using the bot. For the second half of 2026, they're planning a pilot program in Rio's municipal schools, exploring expansion into Angola and Mozambique, and beginning to raise capital from investors to cover operational costs and AI tool expenses. They haven't yet decided whether Mister Pi will ultimately operate as a for-profit company or a nonprofit—but both continue building.
The answer to that chicken-and-rabbit problem, by the way, is twelve chickens and eight rabbits. "You nailed it," the bot replied.
Notable Quotes
One lesson per week for ten or fifteen students was far from sufficient— Felipe Kaplan, creator of Mister Pi
When receiving inappropriate messages or profanity, the bot simply ignored them, but that isn't enough—students need guidance— Felipe Kaplan, reflecting on lessons from his internship at Rio's municipal education department
The Hearth Conversation Another angle on the story
Why WhatsApp specifically? Why not build an app?
WhatsApp is already there. Most students have it. An app means another download, another barrier. This way it's just a contact in their phone.
And the AI part—what's it actually doing that a human tutor couldn't?
It's available at three in the morning. It doesn't get tired. One student can ask the same question five times and get the same patient response. A human tutor can't scale that way.
But can an AI actually teach, or just answer questions?
That's what they're still figuring out. Right now it guides reasoning. The real question is whether students are actually learning better, not just getting answers faster.
Why did Kaplan decide to expand to Angola and Mozambique?
Portuguese-speaking countries with similar education gaps. If it works in Rio's favelas, why not there? But that's also where the money question gets real.
For-profit or nonprofit—does it matter?
It changes everything. Nonprofit means grants and donations. For-profit means investors expect returns. Both can work, but they pull you in different directions.
What happens if the bot doesn't actually improve test scores?
Then they've built something that feels helpful but doesn't solve the actual problem. That's why measuring student progress matters so much right now.