Skip to content

Learn

Subtraction

Level 20 / build-up

3d - 3d (mastery)

4 visual steps / borrow-window subtraction

1. Release hundreds

1. Release hundredsRelease one digit; only borrow stays active.
answer strip
Pay right borrow; release 4: 9 - 4 - 1 = 4.

Pay right borrow; release 4: 9 - 4 - 1 = 4.

2. Release tens

2. Release tensRelease one digit; only borrow stays active.
answer strip
Borrow 10; pay right borrow: 10 - 6 - 1 = 3.

Borrow 10; pay right borrow: 10 - 6 - 1 = 3.

3. Release ones

3. Release onesRelease one digit; only borrow stays active.
answer strip
Borrow 10; release 7: 15 - 8 = 7.

Borrow 10; release 7: 15 - 8 = 7.

4. Read answer

4. Read answerRelease one digit; only borrow stays active.Read answerDrop finished digits; borrow is gone.
Read 4 | 3 | 7 as 437; borrow is gone.

Read 4 | 3 | 7 as 437; borrow is gone.

Practice Level 20

A few quick rounds make each dropped digit feel light; borrow is the only thing to keep.

Start Level