A procedure for finding a square root

HOME

Math Central

Quandaries & Queries

Question from Tracey, a teacher:

Is there a method/process to determine the square root of a large number?

For example, Tiananmen Square's area is 396 900m sq., what is the side length?
I tried thinking find square root of 900, then 6000etc. then put them together, and a few other ways always end up wrong :(.

Thank you,
Tracey

P.S I get the factor tree but don't know what to do with the prime numbers at the end.

Also, can your example be of a larger number like the one above?

Hi Tracey,

There is a procedure/algorithm for finding the square root of a number. It was part of the curriculum when I was in high school in the nineteen fifties. There is an example on a Wikipedia page where the algorithm is explained. It takes some practice to master the procedure.

In the Resource Room on Math Central there is an article titled A geometric view of the square root algorithm which outlines a outlines a geometric argument for the algorithm.

Harley

Math Central is supported by the University of Regina and the Imperial Oil Foundation.