You can find the numerical part of the answer because it is the same on the right side. For example: ¹ <<==== Regrouped 89 + 67 --------- 146 <<=== I had to press space so I could position it.
So that also happens in subtraction, the left side can be found by doing the same steps in the right column. For example: 67 - <<=== this time there was no regrouping 12 ------- 55
