This explanation has made me realize i can’t remember the last time I tried to substract two four digits numbers without a calculator. I’m not even sure I know how
Interesting cultural differences here: the way I learned it, you increment the next digit of the subtrahend (the lower number) on digit underflow, rather than borrowing from the next digit in the minuend. (So it's rather a carry than borrowing.) Anyways, explicit borrow does for a nice explanation.
That is interesting! I could see that make learning it easier since it's closer to addition if you carry instead of borrow. Though one advantage I see to the borrow is, since you're modifying the minuend, you have room to write the modified value of the digit directly above itself.
If I recall this right (it's been a long time, since), initially we marked the column where the carry went by a dot above the minuend. (I guess, it was the same with addition?)
I guess that’s how I would attempt it if I had to- reverse of addition. Just can’t remember when I have had to. Funny how addition and subtraction are unequally distributed in life