Build Your First LLM from ScratchPart 2 · Section 1 of 7
Why a Calculator?
We could teach LLM concepts with any task—chatbot, code generation, translation. But a calculator is perfect for learning. Here's why:
| Criteria | Calculator | Text-to-SQL | Chatbot |
|---|---|---|---|
| Vocabulary | ~30 words | ~10,000 | ~50,000 |
| Training time | 5-10 min | 2-3 hours | Days |
| Data generation | Trivial | Need dataset | Complex |
| Verify correctness | Easy | Medium | Hard |
Key insight: Same concepts, 100x faster iteration. You'll learn tokenization, attention, and transformers—just on a smaller scale.
You might want to jump straight to code generation or chat. But:
- Complexity hides understanding — With a complex task, you can't tell if issues are from your model or your data
- Training time kills iteration — Real LLMs take days/weeks to train. Our calculator trains in minutes.
- The concepts are identical — Tokenization, attention, transformers—it's all the same, just smaller
Once you understand the calculator, scaling up is straightforward.
Helpful?