The math tutor that fits inside a text message - reaching students where the internet doesn't.
DARSEL, STANFORD + AMMAN. The wordmark of a nonprofit that decided the classroom could be a chat thread. Not a screenshot of an app - a company that runs on the oldest phone in the room.
There is a comforting story that education technology tells about itself, which is that the future arrives on a shiny tablet handed to a smiling child. Darsel is built on a less comfortable observation: roughly 40% of the world does not have reliable internet, a lot of children do not have tablets, and if your product requires either one, you have quietly decided who you are not going to teach.
So Darsel does something that sounds almost stubbornly unglamorous. It teaches K-12 math over the channels students already have - SMS, WhatsApp, and Facebook Messenger. A student texts in. An AI-powered chatbot texts back a curriculum-aligned math question, then a hint, then an explanation, then another question calibrated to what the student just got wrong. There is no download. There is no data plan to buy. The tutor is a conversation.
This is the sort of idea that looks obvious in retrospect and was apparently obvious to almost no one, which is usually the good kind of idea.
Texting is ubiquitous even in low-income households, and it struck me as an underutilized resource.- Abdulhamid Haidar, Founder
Jordan → Jordan, India & Nigeria. Distribution by government partnership, not app-store virality.
Over SMS, WhatsApp, or Facebook Messenger - whatever the phone can do.
A curriculum-aligned question from a library of 500,000+, with hints on request.
Adaptive logic spots knowledge gaps and picks what to practice next.
Homework auto-grades; teachers get reports on progress and skill gaps.
An AI tutor delivering practice, hints, and explanations over low-bandwidth messaging, personalized by adaptive algorithms that target each student's gaps.
More than 500,000 curriculum-aligned math questions with step-by-step explanations, spanning grade levels and multiple languages.
Assign homework the platform grades automatically, and read data reports on individual and classroom-level progress.
During the COVID-19 lockdowns of spring 2020, Haidar - who had studied math, computer science, and economics at MIT, then worked at McKinsey - spent a cancelled spring break building a chatbot prototype to deliver math over low-bandwidth channels. He tested it in Nigeria, formalized the nonprofit, and won Stanford's Social Innovation Fellowship in 2021. Darsel joined Y Combinator's Winter 2022 batch. The resume could have pointed at anything; it pointed at kids without wifi.
Darsel is a free, donor-supported nonprofit - but its path reads like a tech company's: an accelerator batch, cloud credits, adaptive algorithms, rapid iteration.
In partnership with the Lagos State Ministry of Basic and Secondary Education, Darsel put its generative-AI tutor in front of more than 15,000 Grade 9 students - who received roughly 5 million personalized answers to their questions.
No teacher was removed from the room. The chatbot handled the repetition; the teachers got the data. That is the quiet thesis of the whole operation: automation as a teacher's amplifier, not a teacher's replacement.
We help kids learn math.- Darsel, stated plainly on its own front page
No smartphone, no app, no data plan required - just the ability to send a text.
The first prototype was built during a spring break the pandemic erased in 2020.
Headquartered near Stanford, much of the operation runs out of Amman, Jordan.
The design premise: only about 60% of people have reliable internet access.
Darsel ran through Y Combinator - unusual company for a donor-funded org.
The number of math questions students have answered on the platform.
▶ Interviews & product demos on YouTube · ▶ Stanford GSB: A math chatbot bridges the digital divide