Maths vs. Making a coffee
There are pros and cons to each method. Some people prefer the old method because it's fewer steps, and trying to go back and forth with the box diagram is confusing. Some people prefer the new method with the box diagram because it's easier to spot a mistake and because you can zone out without losing your place. And some people prefer their own methods because their brains work in unique ways, while other people would consider those methods to be total nonsense.
But this video is one of the worst arguments I've ever seen. If you prefer the old fashioned method, that's reasonable. But you can't accurately compare these two videos shown. One involves someone solving it who already knows how to do it and probably even rehearsed it for the video so they could do it as fast as possible. The other involves a teacher teaching it to a class of elementary school students for the first time and making sure to go slowly enough that every single student has a chance to speak up if they don't understand it. If it was compared to someone using the box diagram who already knew how to do it, it would only take a few extra seconds, and checking your work would be much easier.
I can calculate a date's day of the week in about 5-10 seconds. But if I explained how to do it to a class of elementary school kids, it would take at least a few minutes.
