# What kind of calculator is Marilyn using?

Ask Marilyn ® by Marilyn vos Savant is a column in Parade Magazine, published by PARADE, 711 Third Avenue, New York, NY 10017, USA. According to Parade, Marilyn vos Savant is listed in the "Guinness Book of World Records Hall of Fame" for "Highest IQ."

In her Parade Magazine column of February 25, 2001, Marilyn claims that it is easy to use a Calculator to determine that the square root of 12,345,678,987,654,321 is 111,111,111 (or that 111,111,111 x 111,111,111 is 12,345,678,987,654,321).

## Sorry Marilyn

In order to perform this calculation, a calculator must be able to handle 17 significant digits. Many older calculators can not, although calculators that can are becoming increasingly common.

To check whether your calculator is really capable of handling this task, check the square root of 12,345,678,987,654,320 and 12,345,678,987,654,322, to ensure that the calculator does not report the same square root for values close to 12,345,678,987,654,321.

## Here's One!

Anwis Das <anwisdas@uclink4.berkeley.edu> reports that the Texas Instruments TI-83, which costs about \$85, can perform this calculation.

Readers report that many other calculators are capable of performing this calculation.

http://www.wiskit.com/marilyn/calculator.html last updated May 26, 2003 by herbw@wiskit.com