Im sure the new way works as you say if you are taught it. I can see it I understand what its doing I just dont think I can calculate that way even if I tried.

But to one of your earlier statements we were always taught you were borrowing from columns, so you drew lines down vertically

6|7

-2|8

So in essence you are borrowing from the tens column once, to make the top number greater than the bottom, so the tens column, the 6, loses 1 and becomes a 5, the ones column, the 7 gains from the tens column so 10+7 = 17 then you do 17-8 = 9, with what was left in the tens column you have 5-2 is 3 so the answer becomes 39. When you put it out like that the old system seems about as stupid as the new if you look at the method of teaching objectively.

What im getting at is everyone is right from different perspectives. I dont solve subtraction using either of these methods so eh.