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Addition

Level 4 / foundation

Mixed 1d/2d + 1d

3 visual steps / answer-window addition

1. Fill tens

Step 1: Fill tens
raw windows
running strip
Tens window: 3 + 0 = 3. Hold 3; wait for carry from the next window.

Tens window: 3 + 0 = 3. Hold 3; wait for carry from the next window.

2. Fill ones

Step 2: Fill ones
raw windows
running strip
Ones window: 6 + 9 = 15. Hold raw 15; settle carry later.

Ones window: 6 + 9 = 15. Hold raw 15; settle carry later.

3. Settle carry

Step 3: Settle carry
Settle onceKeep ones; carry moves left.raw windows
settled digits
Settle raw 3 | 15 into 45; keep ones and move carry left.

Settle raw 3 | 15 into 45; keep ones and move carry left.

Practice Level 4

A few quick rounds make digit release automatic; carry is the only thing to keep.

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