Skip to content

Learn

Addition

Level 16 / build-up

3d + 3d (no carry)

4 visual steps / answer-window addition

1. Fill hundreds

Step 1: Fill hundreds
raw windows
running strip
Hundreds window: 3 + 2 = 5. Release 5.

Hundreds window: 3 + 2 = 5. Release 5.

2. Fill tens

Step 2: Fill tens
raw windows
running strip
Tens window: 2 + 5 = 7. Release 7.

Tens window: 2 + 5 = 7. Release 7.

3. Fill ones

Step 3: Fill ones
raw windows
running strip
Ones window: 4 + 1 = 5. Release 5.

Ones window: 4 + 1 = 5. Release 5.

4. Read answer

Step 4: Read answer
Settle onceThe visible windows already read left to right.raw windows
settled digits
Read 575; estimate before submit.

Read 575; estimate before submit.

Practice Level 16

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

Start Level