Oh, fer cryin’ out loud …
Check out this mathematical abomination from — where else? — a Common Core homework assignment:
We feel for the third-graders subjected to that crap. A difference of 145 is reasonable? In what universe?
That would explain so much.
According to our calculations, homeschooling parents might be on to something.
(Thanks to @Maxicat for help with sourcing!)
Just a quick note on the “front-end estimation” method: While it has been taught for decades, it is sadly typical that a Common Core-aligned lesson plan would embrace this flawed estimation technique as a valid way to “check” that an answer is “reasonable.”