I built a tutor that circles your math mistake in red pen

说明与用途

Somo 是一款数学辅导工具，拍照识别手写作业，精准标记错误行并用红笔圈出，随后用学生熟悉的语言解释错误，并提供短课和真实考试题目练习。

问题

Students struggle to understand why their handwritten math solutions are wrong, especially when language barriers exist.

结果

Somo accurately identifies the wrong line in all three handwritten test problems (halving error, dropped minus sign, unequal multiplication). Diagnosis time reduced from ~116 s to ~10 s with failover and circuit breaker logic.

工作流

• Snap a photo of the problem and handwritten work
• Gemini reads handwriting and returns structured JSON with transcription, concept, first wrong line, and explanation
• UI circles the wrong line in red
• Student confirms or corrects the transcription
• Somo streams a short lesson covering the concept, error, analogy, worked example, and exam terms
• Student answers a check question; if correct, they practice a real past‑exam question; if wrong, a simpler re‑explanation is provided

证据

Gemini reads the handwriting and returns structured JSON with the transcription, the concept, the first wrong line, and why it's wrong.

来源

Failover is a feature. Gemini's free quota ran out mid-build. I routed every call through one function: try Gemini, retry once on a 503/429, then fall back to Claude, with a circuit breaker that skips Gemini for 60 seconds after a quota error.

来源

In testing, Somo found the exact wrong line on all three of my handwritten test problems: a halving error (2B = 8 → B = 3), a dropped minus sign when rearranging, and multiplying the two sides of an equation by different numbers.

来源