Subtraction Level 3: 2d - 1d (with borrow). borrow-window subtraction. 1. Release tens42 - 71. Release tensRelease one digit; only borrow stays active.42minus74 - 0 - 1 = 3answer strip3Pay right borrow; release 3: 4 - 0 - 1 = 3.2. Release ones2. Release ones42minus712 - 7 = 5answer strip35Borrow 10; release 5: 12 - 7 = 5.3. Read answer3. Read answerDrop finished digits; borrow is gone.3 | 5 -> 35answer 35Read 3 | 5 as 35; borrow is gone.
