Originally Posted by MotherofToddler
Sure, at the Ph.D. level talent matters but when we are talking about grade school kids learning grade school level math, I really think most kids are have "talent".

I think a large fraction of the population is not smart enough to master the curriculum of an academic high school. In math that would mean getting through Algebra 2.

http://www.nytimes.com/2012/07/29/opinion/sunday/is-algebra-necessary.html
Is Algebra Necessary?
By ANDREW HACKER
New York Times
July 28, 2012

Quote
The toll mathematics takes begins early. To our nation’s shame, one in four ninth graders fail to finish high school. In South Carolina, 34 percent fell away in 2008-9, according to national data released last year; for Nevada, it was 45 percent. Most of the educators I’ve talked with cite algebra as the major academic reason.

Shirley Bagwell, a longtime Tennessee teacher, warns that “to expect all students to master algebra will cause more students to drop out.” For those who stay in school, there are often “exit exams,” almost all of which contain an algebra component. In Oklahoma, 33 percent failed to pass last year, as did 35 percent in West Virginia.

Algebra is an onerous stumbling block for all kinds of students: disadvantaged and affluent, black and white. In New Mexico, 43 percent of white students fell below “proficient,” along with 39 percent in Tennessee. Even well-endowed schools have otherwise talented students who are impeded by algebra, to say nothing of calculus and trigonometry.

A substantial fraction of the population cannot use arithmetic to solve simple problems and does not meet the standard one would expect of a junior high school graduate.

Charles Murray's book "Real Education" (p36, can be read on Google books) mentions the results for the following 8th grade NAEP question.

Quote
There were 90 employees in a company last year. This year the
number of employees increased by 10 percent. How many employees
are in the company this year?
A) 9
B) 81
C) 91
D) 99
E) 100
Only 36.5% of 8th-graders got the correct answer, D. Bright people tend to associate with other bright people (and nowadays, marry them), and I think some have an unrealistic idea of what an IQ of 85 or 100 means.