Skip to content

Learn

Addition

Level 27 / mastery

4d + 4d (ones carry)

5 visual steps / large answer-window addition

1. Fill thousands

Step 1: Fill thousands
raw windows
running strip
Thousands window: 3 + 2 = 5. Hold 5; wait for carry from the next window.

Thousands window: 3 + 2 = 5. Hold 5; wait for carry from the next window.

2. Fill hundreds

Step 2: Fill hundreds
raw windows
running strip
Hundreds window: 6 + 5 = 11. Hold raw 11; settle carry later.

Hundreds window: 6 + 5 = 11. Hold raw 11; settle carry later.

3. Fill tens

Step 3: Fill tens
raw windows
running strip
Tens window: 4 + 7 = 11. Hold raw 11; settle carry later.

Tens window: 4 + 7 = 11. Hold raw 11; settle carry later.

4. Fill ones

Step 4: Fill ones
raw windows
running strip
Ones window: 8 + 9 = 17. Hold raw 17; settle carry later.

Ones window: 8 + 9 = 17. Hold raw 17; settle carry later.

5. Settle carry

Step 5: Settle carry
Settle onceKeep ones; carry moves left.raw windows
settled digits
Settle raw 5 | 11 | 11 | 17 into 6227; keep ones and move carry left.

Settle raw 5 | 11 | 11 | 17 into 6227; keep ones and move carry left.

Practice Level 27

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

Start Level