Teachers have been taught not to teach actual information, but to try to get kids to learn how to learn--like that isn't innate. A simplistic version of teachers' thinking is that with all the information in the world at their fingertips, all kids really need to know is how to Google.
However, most parents aren't fooled; some can afford remediation, some can't (from "Banality"):
The premise is simple. If public schools don’t teach algebra or chemistry or history or great literature or how to write well—the old-fashioned learning that has been around for centuries and remains high status knowledge in most cultures—rich kids will get it somewhere else. Poor kids won’t.
From the same "Banality" article:
The first graders were being taught addition of two-digit and one-digit numbers using word problems. [...] Three acceptable strategies were shown for solving the problem. All involved “chunking” the numbers into groups (in the case of fifteen, three groups of five or one group of ten and another group of five), with each group presented in a circle or box. The groups are then added together. The addition must be shown graphically.
One unacceptable strategy was also shown:[...] Please do not have your child stack numbers [traditional algorithm].
[One kid's parents] were alarmed that the standard algorithm for addition was being discouraged, let alone not being taught as the simplest, most efficient method for solving addition problems. [...]
A compromise was struck [with the school]. Solutions using standard algorithms would not be marked wrong, the parents were told, but their son would be required to “illustrate his understanding” through graphical representations of math problems. In his blog, [the parent] includes a worksheet that shows the laborious process his son went through, drawing with the uncertain strokes and still developing fine motor skills of a first grader, to prove that three tens make a total of thirty and three fifteens make a total of forty-five.
This is another reason why boys tend to lag girls right from the start. In general, girls' fine motor skills develop before those of boys. Boys have more trouble sitting for laborious tasks, have poorer pencil control, and report more hand pain than girls (see Ralph Fletcher's "Boy Writers").
In the case of the particular child discussed above:
Which goes back to the first point: parents with options, who are generally wealthier than those without options, will exercise them, leaving poorer kids stuck and left behind.The [parents] observed several classrooms using CGI for math instruction at the school. They eventually withdrew their children and sent them to private school.