Just shaking my head at this one…

Via Liberty Unyielding:

A sample math problem posted by a frustrated mother at will have you wondering if developers of Common Core materials can do simple arithmetic. The mother, Trisha Haas, laments that mastering “Common Core math” is a “massive struggle” for her third-grade daughter, Charlotte.
If the problem, which is reproduced below, is any indication, Charlotte is not the one with the difficulties.

Notice that the writer who created this problem seems totally unfamiliar the rules of “rounding.” As you almost certainly remember from your own elementary school days, to round 354 to the nearest hundred, you look at the digit in the tens column. If it is 5 or greater (as it is here), you round up (in this case to 400). But the writer seems to think you should round down, to 300.

The second number, 291, is an even more glaring example. As Haas quips:
I can tell you that if I estimated or rounded off my bills from $291 to $200, I would get a notice of an unpaid bill. I am not sure my mortgage or car payment would agree with that.

Just as puzzling is the conclusion arrived at. If the estimated sum is 500, as the writer wrongly suggests, then how is 645 a reasonable answer?
As a wise man suggested to me, this is a case of education getting in the way of learning.