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Topic: Common Core snippet a little distressing
Replies: 73   Last Post: Jul 26, 2013 6:27 PM

 Messages: [ Previous | Next ]
 kirby urner Posts: 3,690 Registered: 11/29/05
Re: Common Core snippet a little distressing
Posted: Jul 14, 2013 12:48 PM
 att1.html (2.4 K)

If you shaped the bags into uniform-sized polyhedrons and fit them together
seamlessly, like bricks, to form this growing tetrahedron, then you would
be showing what the cube people show. The cube people show smaller bricks
making the bigger cube. Here, we have an octahedron and tetrahedron that
together fill space.

Another demo would be to take a glass or clear plastic tetrahedron and bury
the tip in the sand so it stays upside down. Pour liquid into it using a
unit tetrahedron measuring cup. Mark the positions 1, 8, 27, 64... and
notice they are equally spaced up the side.

Unlike a cube, when you slice a regular tetrahedron parallel to any side,
you still have a regular tetrahedron. Nice property. Slice a cube that
way and you have a cube no longer.

Kirby

On Sun, Jul 14, 2013 at 9:38 AM, Robert Hansen <bob@rsccore.com> wrote:

>
> On Jul 14, 2013, at 12:05 PM, kirby urner <kirby.urner@gmail.com> wrote:
>
> You have allowed yourself to get side-tracked by a non-issue. It's not
> just an analogy, it's a perfectly good model of 3rd powering that doesn't
> happen to use a cube. This is what Common Core will lead to, a hardening
> of the mental arteries such as you're experiencing now. By adulthood, it
> may be irreversible.
>
>
> But that doesn't make any sense. I could just stack bags of dirt in the
> order of 1, 8, 27, 64, ... and call it 3rd powering, but where would the
> intuition be in that? That is a requirement for teaching, is it not? First
> we had a poster that identifies intuition with reason and now we have one
> that identifies it with rhetoric.
>
> Bob Hansen
>
>

Date Subject Author
7/13/13 Peter Duveen
7/13/13 Robert Hansen
7/13/13 kirby urner
7/14/13 Robert Hansen
7/14/13 kirby urner
7/14/13 Robert Hansen
7/14/13 kirby urner
7/14/13 Robert Hansen
7/14/13 Robert Hansen
7/14/13 kirby urner
7/14/13 Robert Hansen
7/14/13 kirby urner
7/14/13 Robert Hansen
7/15/13 kirby urner
7/14/13 Wayne Bishop
7/14/13 kirby urner
7/14/13 Wayne Bishop
7/15/13 kirby urner
7/15/13 Robert Hansen
7/15/13 Christian Baune
7/15/13 kirby urner
7/16/13 Wayne Bishop
7/16/13 kirby urner
7/14/13 Wayne Bishop
7/14/13 Joe Niederberger
7/15/13 Joe Niederberger
7/15/13 Joe Niederberger
7/15/13 Robert Hansen
7/15/13 kirby urner
7/15/13 Robert Hansen
7/16/13 kirby urner
7/16/13 Robert Hansen
7/17/13 kirby urner
7/17/13 Robert Hansen
7/17/13 kirby urner
7/17/13 Robert Hansen
7/17/13 kirby urner
7/15/13 CCSSIMath
7/16/13 Joe Niederberger
7/16/13 Robert Hansen
7/16/13 kirby urner
7/17/13 Joe Niederberger
7/17/13 Robert Hansen
7/17/13 kirby urner
7/17/13 Robert Hansen
7/17/13 kirby urner
7/17/13 kirby urner
7/17/13 Robert Hansen
7/18/13 Wayne Bishop
7/17/13 Joe Niederberger
7/17/13 Joe Niederberger
7/17/13 Robert Hansen
7/18/13 Wayne Bishop
7/18/13 Joe Niederberger
7/18/13 kirby urner
7/18/13 Joe Niederberger
7/20/13 kirby urner
7/19/13 Joe Niederberger
7/19/13 kirby urner
7/19/13 Joe Niederberger
7/19/13 Joe Niederberger
7/20/13 kirby urner
7/21/13 Joe Niederberger
7/23/13 kirby urner
7/24/13 frank zubek
7/24/13 frank zubek
7/24/13 kirby urner
7/25/13 frank zubek
7/25/13 kirby urner
7/25/13 frank zubek
7/25/13 frank zubek
7/25/13 frank zubek
7/26/13 frank zubek
7/26/13 frank zubek