[snowman]

Teachers who teach math really need to know the subject for a lot or reasons. In the third grade I constantly argued with my teacher about being able to divide a small number by a larger number, ie a fraction. She said it was impossible. I said that if I have a single item I can always cut it up into smaller pieces. This problem persisted until college, where I learned the truth, The teachers didn't know what they were talking about. They didn't understand math. The teachers that I had, never understood the concepts. I am not a marvelous math student, so how do teachers cope with someone like one of my sisters, at 8th grade level or above in second grade. Math teachers really NEED to understand math to teach it. I suspect many do not.

In any case, I don't believe anyone should use a calculator until the 12 th grade and only then if they are proficient at that grade level. That’s the same grade slide rules used to be introduced.

As to "bone head" math, please excuse the term, but it is most descriptive, yes use calculators.