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Multiplication

Level 17 / build-up

3d x 3d (small)

6 visual steps / multi-digit window train

1. Left Edge

1. Left Edge
 raw windows
2x1 = 2. Raw fits.

2x1 = 2. Raw fits.

2. Left Cross

2. Left Cross
 raw windows
2x2 + 3x1 = 7. Raw fits.

2x2 + 3x1 = 7. Raw fits.

3. Center Stack

3. Center Stack
 raw windows
2x4 + 3x2 + 1x1 = 15. Carry waits for settle.

2x4 + 3x2 + 1x1 = 15. Carry waits for settle.

4. Right Cross

4. Right Cross
 raw windows
3x4 + 1x2 = 14. Carry waits for settle.

3x4 + 1x2 = 14. Carry waits for settle.

5. Right Edge

5. Right Edge
 raw windows
1x4 = 4. Raw fits.

1x4 = 4. Raw fits.

6. Settle strip

6. Settle strip
Settle onceRaw windows keep ones; extra carry moves left.raw windows
settled strip
2 | 7 | 15 | 14 | 4 -> 28644.

2 | 7 | 15 | 14 | 4 -> 28644.

Practice Level 17

A few quick rounds make the train automatic; each raw window keeps one digit.

Start Level