I was helping my daughter with her homework. 
She said her teacher didn’t want her carrying over tens the way I was showing her, “she hadn’t taught it to them yet.”
Stumped by that one, the best I could suggest was doing it anyway and erasing the evidence.
- 5+7 = 12,
 - write 2 in the ones place,
 - carry the ten into the tens place,
 - 10+20+30 = 60,
 - write the 6 in the tens place,
 - ERASE the hell out of that damn ‘1’ so you don’t get a crying child who hates arithmetic…