# Poll: the sum(7,9)

Jerry Balzano gjbalzano at popmail.ucsd.edu
Tue Mar 15 12:35:43 CST 2005

```I actually think of the numbers as "characters" (agent-based
computation?), so "9" has its own characteristic "9-behavior", "8" has
its own "8-behavior", and so on.  Everybody, I would claim, learns
"10-behavior", for example.  So the interesting question becomes, how
many integers have "characters" like this?  My answer would be that,
within limits, most of numbers under 100 have some kind of character,
although in some cases the "character-sketch" would be pretty meager.
At least, most of them have a "prime vs. composite" flag filled in, and
if they're composite, then part of their character includes what their
factors are.  Of course, these aspects of their character are more
important for multiplication and division than for addition and
subtraction.  For the latter, "13" inherits character from "3" mostly
but also a little from "1".  And "38" has mostly "8" character but also
a little "3" character and even a tiny bit of "4" character (because
it's closer to 40 than to 30; add 38? under some circumstances I'll use
the "4" character of 38 and "add 40", then "subtract 2", along the
lines that some people have posted).  Welcome to the world of
anthropomorphic epistemology ....

- Jerry

On Mar 14, 2005, at 8:38 PM, Mark Swindell wrote:

> I've got a question I'd be interested in hearing from as many of the
> list as care to respond.
>
> It's this:  How do you mentally process simple addition/subtraction
> facts?  What actually happens in your brain to elicit 16 when you hear
> 7+9? (for example)

On Mar 14, 2005, at 10:09 PM, Mark Swindell wrote:

> To clarify:  7 and 9 were arbitrary numbers.  It could have been any
> two single digit addends.  I didn't mean to focus on the manipulating
> the 9 factor.  3 and 5, 6 and 8, what process do you use to instantly
> know, or are there calculations involved?

```