---
license: odc-by
task_categories:
- text-generation
language:
- en
tags:
- math
- code
- education
- k12
size_categories:
- 1M<n<10M
---

# K-12 Math & Coding Dataset

A ~2 billion token dataset built for K-12 math and coding education use
cases: **1,004,991,667 tokens** of math content and **1,020,505,114 tokens**
of code content, both comfortably over the 1B-token target for each
category.

## Dataset Summary

| Category | Tokens | Rows | File |
|----------|-------:|-----:|------|
| Math | 1,004,991,667 | 676,018 | `math/final.jsonl` |
| Code | 1,020,505,114 | 937,248 | `code/final.jsonl` |

Built via a 6-phase pipeline: source collection → cleaning (PII redaction,
boilerplate/spam removal, encoding fixes) → deduplication (exact SHA-256 +
fuzzy MinHash LSH) → heuristic quality filtering → budget-controlled final
sampling → manual quality audit. Full methodology, per-source breakdowns,
and known limitations are in `final_report.md`.

## Schema

Each line is a JSON object:

```json
{
  "text": "...",
  "source": "finemath4plus",
  "category": "math",
  "quality_score": 4.3,
  "token_count": 512,
  "language": "en",
  "metadata": {}
}
```

- `quality_score`: populated only for `finemath4plus` (has an upstream
  classifier score); `null` for all other sources.
- `language`: natural-language code (all records verified predominantly
  English). For code records, the actual programming language is under
  `metadata.programming_language`.
- `metadata`: source-specific extra fields (URL, license, file path, repo
  name, exercise name, difficulty, etc. — varies by source).

## Sources

**Math**: FineMath 4+, OpenWebMath, GSM8K, MATH (hendrycks_math).
**Code**: GitHub Code (Python/JavaScript/Java/HTML/CSS via
`codeparrot/github-code-clean`), freeCodeCamp, Exercism, APPS, CodeContests.

## Token Counting

All token counts use the `tiktoken` `cl100k_base` tokenizer, computed via
exact `encode_ordinary()` calls (not estimates) at every pipeline stage.

## Quality Audit

Both categories were manually spot-checked twice (once pre-assembly, once
on the final sampled corpus). Code passed cleanly at every check (~90-94%
good, 0-2% bad). Math's final spot-check found a 15% "bad" rate (above the
10% target threshold) driven by several low-frequency, hard-to-cheaply-filter
patterns (AI-generated SEO filler, off-topic forum comment dumps, one
essay-mill advertisement, thin template pages) — documented as an accepted
residual limitation rather than silently delivered. **See `final_audit.md`
and `final_report.md` Section 8 for full detail before using this dataset
for anything quality-sensitive.**

## Known Limitations

See `final_report.md` Section 8 for the complete list, including:
math corpus residual bad-rate, AMPS/OpenStax not sourced, The Stack v2
substituted with GitHub Code due to gating, freeCodeCamp/Exercism volume
shortfall, and HTML's residual auto-generated-doc contamination.

## License

Source licenses vary per record — see `metadata.license` for code records
where available. FineMath 4+ and OpenWebMath are ODC-By. Aggregate dataset
provided as-is for research/educational use; verify individual source
licenses before redistribution.