On Wed, 15 Sep 2004, Devin Weaver wrote:

> I am an Emergency Medical Technician. One of the valuable piece of
> information is a persons date of birth coincided with there age. I always
> hated asking people what there age was. So I thought I could figure it out
> from there date of birth. Or if the patients are unconscious I could get
> there divers license.
> The problem was I can't do that kind of math in my head nor can I carry a
> calculator around.
> I found Chisenbop saves me time and mental energy here is the process I
> use to quickly grab an age. This first technique is fast and will narrow
> down the age with in a year. The second technique takes the first and
> narrows down the age exactly.
> One. Get the year the patient was born (For example 1942)
> Now place your hands all extended to represent 99. Now remove fingers
> corresponding to the two significant digits of the year. So pull back 4
> fingers from the left hand and two from the right hand (This leave a
> representation of 57)
> Since the current year is 2004 we count / add four to the right finger
> carrying as described in Chisenbop. Leaving a result of 61.
> This is either there exact age or is one year less then there exact age.
> Two. The exact age can be determined by looking at the day and month of
> there date of birth. if there birthday has passed this year then add on to
> the count of four above. For example if the date of birth is January
> first, 2004 you would add 5 above. If the date of birth was December 30,
> 2004 you only add four.