Numbered switches on my dash

You probably encountered Common Core. A form of .. abacus in the Chinese syntax generated to get a hours worth of sweat and work out of the wee ones in class on paper. (Plural, many pencils and paper)

2+2=4 is verboten. Not allowed, not legal etc in school house.

What they want is this.

2 = II
2 = II

so IIII = 4

minus 2 II = 2 II thus problem is valid both ways.

I hate to see them add up this crap inside a Walmart store.