An average IQ for the traditional American Caucasian population was, by definition, 100.
For Caucasians, a person with a "slightly lower than normal IQ" is in the 90's.
With the disclaimer that I am not an expert in the education of low-IQ children, I am very, very dubious that children with IQ's in the 90's can learn any algebra.
My best guess is that a child would need an IQ out in the 105-110 range in order to so much as attempt to tackle algebra, and, even then, it would be very, very rough going, with no guarantee of success.
Of course, our problem [really, our looming catastrophe, which will rip this nation apart at the seams, no later than about 2020] is that Blacks and Aboriginal/Mestizo Hispanics both have IQ bell curves whose AVERAGES are no higher than about 85 - i.e., on average, Blacks and Aboriginal/Mestizo Hispanics are what Caucasians would consider to be mildly retarded.
The reason this will tear the nation apart is because the American Caucasian [and Asian] numbers are in freefall, and the Blacks and Aboriginal/Mestizo Hispanics now provide almost half of all the children in the USA:
Of U.S. Children Under 5, Nearly Half Are Minorities
By D'Vera Cohn and Tara Bahrampour
Wednesday, May 10, 2006; Page A01
washingtonpost.com...Forty-five percent of U.S. children younger than 5 are minorities...
Statistical Abstract of the United States
Section 1, Population
[see especially Table 8 & Table 9, pages 11-13]
PDF FILE: pop.pdf
It does not take an IQ of 110 to “attempt” algebra. Basic algebra is certainly within reach of those with ~90 IQ. My youngest brother has mental retardation and an IQ of something probably around 80 and he could be taught basic algebra with some work (I’m talking about “find the unknown in the set of equations” algabra, not necessarily binomial theory)
I don’t know, I had quite a few white students in the class I taught (see above) and they were pretty darn dumb. Maybe it’s not right to call them dumb because certainly next to NOTHING was expected of them. They were there to get college degrees and they were paying for it - it was almost an offense to ask any of them to do any actual real studying.