When I first read the prompt and the list, I thought, this is easy. His list is great. Then I started reading other people's responses and started to wonder. Many felt that important things were left out (areas, volumes, algebra, create/derive formulas, fractions, etc.). I thought, of course these are also important. And, as Lisa points out, why are transformations on the list instead of what seems to be more basic geometry skills.Then I read again that this is a list of "non-negotiable basic skills for mathematics" and I started to wonder what would make an item a *basic* skill. As Lisa and others' point out, this is what we want for all students. But, isn't the list of what we want for *all students* the Common Core?

As Ruth pointed out, Leinwand says these skills are to achieve the goals of solving everyday problems, communicating understanding, and representing and using mathematical ideas. If that is the case, leaving out skills for finding volume/area would be needed. (Plenty of everyday problems there!)

I have decided that basic skills might best be defined as the skills that are necessary to achieve the conceptual understandings presented in the common core and to be fluent (efficient) in solving mathematical problems. When I look at the list through that lens, it seems to make more sense. For example, if a student understands the "attributes of 2 and 3 dimensional shapes", they understand volume and area and so could find methods for finding the volume/area. I'm still not totally satisfied that his list is the "best" or most complete or least redundant list of basic skills, but it is a good place to start and get me thinking. What is obvious to me is that my childhood exercises in long division are not necessary in the world I live in now.

As an aside, I decided to do an estimating check on one of C. Wolfram's statistics (from the TED talk pointed out by Angela). **Please check my math and reasonableness of my assumptions.**

He said that 106 lifetimes were spent teaching hand calculating today.

100 yrs/lifetime x 100 lifetimes = 10,000 yrs x 365 days/year=

3,650,000 days (4,000,000 days) x 20 hrs/day=

80,000,000 hours teaching hand calculating in a day.

There are about 7 billion people on earth, perhaps 1 billion in school

If each child spent .1 hours (6 minutes) practicing/learning hand calculating we would reach 100,000,000 hours. Seems to me that Conrad's statement is reasonable.