Lathoa launches kids math app that deliberately makes mistakes

A children's math app called Lathoa was introduced in a Hacker News post on September 30, 2026. The write-up comes from the person who made it, who says the app is aimed at kids around 10 to 14 years old. The core mechanic is a robot named Errol who solves a math problem step by step, with one of those steps deliberately wrong. The child's job is to find the bad step and say what is wrong with it.

That the errors are not guaranteed matters to how the app plays: because some problems are correct throughout, a child cannot get by with a blanket "there's a mistake" every time. When a child does flag an error, an explanation has to be typed in before the larger XP reward is granted, and how quickly the answer comes in also feeds into the score. According to the same description, the app does not offer any direct conversation with an LLM.

The framing puts the emphasis on the child evaluating a piece of reasoning and articulating the flaw, rather than letting a model hand over the answer. The post does not give a release date, supported platforms, or pricing. As of this report, that is where the story stands: Lathoa has been described in one Hacker News post, and no further developments have been reported.