Not sure, what it implies, but I couldn't wrap my head around exactly what pre-algebra is. I found this document at the Santa Fe Schools website that gives a neat alignment to common core with degrees of emphasis per subject area.
http://www.sfps.info/documentcenter/view/6764Looking through, I'd have more concern with translating terminology than mathematical basis. Things like "constant of proportionality" or "decimal expansion" that are represented by other terms in older texts. I also notice some geometry concepts like congruence that were introduced after algebra when I was in school.
