Here’s another gem from the good folks at Common Core:
If 5/2 and 100/T are viewed as unit rates obtained from the equivalent ratios 5:2 and 100:T, then they must be equivalent fractions because equivalent ratios have the same rates.
This is but one gem in 15 pages of Talmudic exegesis on ratios and proportional reasoning at sixth and seventh grade.
Well, if you’ve read any of Wu’s lengthier articles (e.g., the one on his website that more deeply “explains” fractions to elementary teachers), you can’t be too surprised that the Common Core is filled with such golden nuggets of prose. It actually is possible to make sense of mathematics, but you’d never know it from reading Wu and similar Math Warrior writing. I imagine Wu MEANS to be sensible, but I’m not so sure about most of those folks: they seem to like keeping the craft well-protected from mass understanding. Makes them feel so special.
That does seem like rather turgid prose. The problem is with the English, rather than the math. I dislike the proliferation of terms (ratio, unit rate, fraction) for a single concept. The distinction between equality and equivalence, though important at a high enough level in math also seems irrelevant for K–12 math.