Step-by-step worked examples in 15 seconds.

It's an AI tool that turns a skill prompt (for example, "long division with two-digit divisors" or "Krebs cycle ATP yield") into one or more fully solved worked examples. Each example contains a problem statement, a strategy callout that names the approach, numbered steps with both the action and the rationale, the final answer, and an optional check-yourself prompt the learner can use to verify their work. It is purpose-built for the way teachers model new skills in class — sometimes called "I do, we do, you do" or "gradual release of responsibility" instruction.

All of them. The AI prompt is grade-band-aware — pick Elementary (K-5), Middle (6-8), High School (9-12), College, Adult / Test Prep, or Mixed, and the model calibrates vocabulary, complexity, and step granularity. Subjects: Math (arithmetic, fractions, algebra, geometry, trig, pre-calculus, calculus, statistics, discrete), Science (biology, chemistry, physics, earth and environmental science), ELA / Writing (reading comprehension, essay scaffolds, grammar, rhetorical analysis, literary devices), Social Studies (history, civics, geography, economics), Language (vocabulary, conjugation, grammar drills in any major world language), and Test Prep (SAT, ACT, GRE, GMAT, LSAT, MCAT, AP, IB, NEET, JEE, UPSC, CFA, FRM, PMP, USMLE, AWS, Azure, GCP, CompTIA, Cisco, etc.). For genuinely novel topics, pick Other / General and describe the skill in detail.

24 hours from the moment you click Save & share. After that the set is automatically and permanently deleted by Firestore's TTL sweeper — there is no way to recover it. This is the same anonymous-retention pattern as Quick Cards and Live Audience Survey, intentionally short to keep the feature lightweight, privacy-friendly, and free. The 24-hour limit is shown both in the share panel and on the shared-set banner so anyone opening a link knows when it expires. Need a permanent record? Download the Solution PDF or Worksheet PDF before the link expires — the file is yours to keep.

Yes — every set offers two one-click downloads. Solution PDF is the teacher-facing reference: title page, every example with strategy + numbered steps + rationale + answer + check-yourself, footer with the share URL. Worksheet PDF is the student handout: problems only, with eight blank ruled lines under each problem for showing work, plus an Answer line. Both are Letter-sized (8.5 x 11 inches), 0.75-inch margins, generated entirely client-side (no backend round-trip), and can be downloaded for a draft (unsaved) set OR a saved set. File names follow the pattern worked-examples-{slug-or-draft}-{variant}-{date}.pdf so they sort cleanly in any LMS or shared-drive folder.

The AI prompt is engineered for instructional accuracy — every example MUST have a non-empty problem, a stated strategy, at least three numbered steps, and a final answer. The server validates structure on every response and discards examples that fail; if the count of valid examples after validation is zero, the server makes one corrective retry before returning a soft error rather than ever returning misleading content. We also use grade-band-specific style guidance so the rationales actually match the cognitive load of the chosen audience. We still recommend a quick read-through before high-stakes use — AI is a strong assistant, not infallible. The check-yourself prompt at the bottom of each example is intentionally there to flag computational mistakes the model might miss.

Yes, completely free. No signup, no email, no credit card. Generate, download PDFs, and share — all anonymously. The only data we store on the server is the saved-set Firestore document (and only when you tap Save & share), and even that auto-deletes after 24 hours. Per-IP rate limits are in place to protect the AI quota; in normal classroom use you will never hit them.

Yes — mobile-first. Tap targets meet WCAG 2.5.5 (minimum 44 x 44 px), the layout reflows cleanly down to iPhone SE width (375 px), and PDF downloads work on iOS Safari and Android Chrome via the browser's native save dialog. The PDF generator is dynamically imported on first PDF click so you don't pay the 400 KB jsPDF cost until you actually need it.

Quick Cards are flashcards (front + back, study-by-flip, 4-rate scheduler) — best for memorization, vocabulary, definitions, and quick recall. Quick Quiz is a 4-option multiple-choice quiz with a correct-answer key — best for assessment and exam-style fact recall. Worked Examples is fundamentally different: a fully solved step-by-step example, with strategy and rationale, designed for the teaching moment when a concept is brand new and the learner needs to see how to think through it, not just whether they got it right. Use them together: model with Worked Examples → drill recall with Quick Cards → assess with Quick Quiz.