[nfb-talk] abacus needed

Michael Bullis mabullis at hotmail.com
Mon Feb 9 16:22:24 UTC 2009


Hi Terrie:
I'm not a teacher and I may be confused.  But, having said that, and
recognizing that being wrong never stopped me, let me explain why I think
that ten beads is better for small children.
Picture adding eight plus three  on an abacus with nine beads.  You put
eight beads down and then want to add three more.  You add one bead and then
must know that in order to add two more beads you have to bring down a bead
on the tens row and bring down one bead on the ones row.  

For kids, it makes more sense to them if you are able to bring down two
beads on the ones row.  Now since you have filled up the ones row with
beads, you trade that in for a single bead on the tens row.  You know that
you brought down two beads before running out so now you can bring down one
more bead.  So, in front of you now you have one bead on the tens row and
one bead on the ones row.  So, you have eleven.

For base 10 I agree with you that there are only nine units possible and for
representational purposes nine beads make sense.  But with small children,
we're not talking about base 10 and logic.  We're talking about counting.
We started with ten fingers for counting purposes.  Every time we reached
ten on our fingers we made a mark on the ground or whatever and then started
again with our fingers.  That makes sense to kids and it made sense to us in
our past.  No, there isn't a way to express ten with a single number so we
use a one and a zero.  But, with fingers and with beads the ten can still
exist.

Hope this confuses you thoroughly (laugh).
Mike
 

-----Original Message-----
From: nfb-talk-bounces at nfbnet.org [mailto:nfb-talk-bounces at nfbnet.org] On
Behalf Of Powers, Terry (NIH/OD/DEAS) [E]
Sent: Monday, February 09, 2009 8:17 AM
To: mabullis at hotmail.com; NFB Talk Mailing List
Subject: Re: [nfb-talk] abacus needed

Mike;
How can you have ten beads, it should be nine.  Our numbers go zero to nine.
Then we go to the next tolumn or the tens.
I have only used the one with a bead for five and four one beads.

Terry Powers
 

-----Original Message-----
From: Michael Bullis [mailto:mabullis at hotmail.com]
Sent: Sunday, February 08, 2009 5:03 PM
To: 'NFB Talk Mailing List'
Subject: Re: [nfb-talk] abacus needed

Actually, I have found the cranmer abacus at aph as Ken suggests.  I'm
looking for a ten bead abacus but I don't know what that's called.  I think
math makes more sense to kids when there are ten beads.  The value of the
cranmer was in speed of use but in early learning I liked the ten bead.
Mike
 

-----Original Message-----
From: nfb-talk-bounces at nfbnet.org [mailto:nfb-talk-bounces at nfbnet.org]
On Behalf Of Alicia Richards
Sent: Sunday, February 08, 2009 4:32 PM
To: mabullis at hotmail.com; NFB Talk Mailing List
Subject: Re: [nfb-talk] abacus needed

Mike, are you talking about a Cranmer abacus, or something different? 

Alicia 

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