The common-core crap assumes that each step would take equal amounts of time. As long as there’s one approach that they’re comfortable doing and that WORKS, who gives a fuck what approach they use?
If I were doing it in my head, I’d probably say that 500 – 475 = 25. 511 – 500 = 11. 11 + 25 = 36. Basically the third method without the silly little 1 added.
