Poll: the sum(7,9)

[Mark Swindell]

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?

Mark

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

> 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)