Skip to content Subtraction Level 27: 4d - 4d (borrow ones). borrow-window subtraction.
1. Release thousands
8 - 3 = 5; drop 5.2. Release hundreds
6 - 2 = 4; drop 4.3. Release tens
Pay right borrow; release 2: 4 - 1 - 1 = 2.4. Release ones
Borrow 10; release 5: 12 - 7 = 5.5. Read answer
Read 5 | 4 | 2 | 5 as 5425; borrow is gone.