# Cargo Filling — Document 2

Addition crossing the **tens** boundary (odd pages) and the **twenties** boundary (even pages).
10 pages, 6 cards per page, 60 problems total.

Same ships, asteroids, hero/footer images and element positions as Document 1 — **only the numbers changed**
(positions are preserved via `cargo-filling-2.data.json`, copied from Doc 1; page 10 reuses page 2's layout).

## Crossing rule (the only difference from Doc 1)

- **Odd pages (1, 3, 5, 7, 9)** — cross **10**: cargo capacity badge = `10`, A already in cargo (1–9),
  N = 10 − A, brace value `10`.
- **Even pages (2, 4, 6, 8, 10)** — cross **20**: cargo capacity badge = `20`, A already in cargo (11–19),
  N = 20 − A, brace value `20`.
- **Floating asteroid B is always 1–9** on every page. The child splits B = N + M so A + N hits the boundary.
- Full expression: `A + B = (A + N) + M = C`.

Numbers are **randomly spread**: each page draws 6 **distinct** A values spread across the whole valid
A-range, each paired with a varied B (preferring B values not yet used on the page). Only the constraints
you set apply: asteroid B=1–9, capacity 10/20, crossing with non-zero fill N and non-zero remnant M.
Generated with seeded RNG (`mulberry32(20260622)`) in `/tmp/build-cf2.cjs` so the set is reproducible.

Card 1 of page 1 is the worked **example** (answers filled in handwriting style): A=5, B=9 → N=5, M=4, C=14.

## Numbers per page (A + B)

| Page | Boundary | Problems (A+B) |
|------|----------|----------------|
| 1 | 10 | 5+9, 3+8, 4+7, 2+9, 6+6, 9+4 |
| 2 | 20 | 19+3, 17+4, 15+6, 18+7, 14+9, 12+9 |
| 3 | 10 | 3+8, 5+6, 6+7, 2+9, 8+5, 4+8 |
| 4 | 20 | 12+9, 18+3, 19+2, 14+9, 17+5, 16+7 |
| 5 | 10 | 9+2, 3+8, 5+7, 7+5, 8+3, 4+9 |
| 6 | 20 | 16+5, 14+7, 17+9, 12+9, 19+8, 15+6 |
| 7 | 10 | 5+6, 6+5, 7+7, 8+4, 3+8, 2+9 |
| 8 | 20 | 18+9, 12+9, 17+5, 19+3, 15+8, 13+9 |
| 9 | 10 | 8+6, 4+7, 5+9, 9+3, 6+5, 3+8 |
| 10 | 20 | 17+7, 18+6, 13+8, 16+9, 15+6, 19+2 |

## Hero orientation

Odd pages = hero on the right (`flex-row-reverse`), even pages = hero on the left (matches Doc 1 convention).
Page 10 reuses page 2's hero/footer (splitter6 / cabin3).