Michelle Malkin is on a little Jihad today against Mayan Math. Mayan Math in US schools The laudable goal is to get the kids more engaged, but this kind of thing works real badly in practice. My son was exposed to lattice multiplication in 4th grade, and it set him back a whole lot. He brought his home work, and it confused the heck out of me, and he lost ground for the year. I am all for exposure to interesting varied ideas, but math is more important that fuzzy feelings of goodwill. I am wiling to concede the Mayans were pretty good at astronomy. But I am not interested in astronomy at the 4th grade level, I am interested in understanding solutions.