>From the Platte Co., MO, Historical/Genealogical Society: In the event you don't have a computer close at hand to do the calculating: REMEMBER 8870. That's not an error: It's the number to remember when you want to find the birth date of someone when you only have the date of death and age. How do you figure the birth date? Suppose the person died May 6, 1889, at the age of 71 years, 7 months, 9 days. *Write the year, month, & day as:------------------------ 18890506 *Subtract the age at death:---------------------------------- 710709 *This give the figure -------------------------------------------- 18179797 *Now subtract 8870 -------------------------------------------- 8870 *The result is ----------------------------------------------------- 18170927 Year 1817, 9th month (Sept.), 27th day----- or 27 Sept. 1817.