# Math help needed (not homework!) **URL:** \ **Category:** Factual Questions\ **Created:** [March 26, 2005, 11:54am UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343 "2005-03-26T11:54:02Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![unclviny](https://avatars.discourse-cdn.com/v4/letter/u/e274bd/32.png) [@unclviny](https://boards.straightdope.com/u/unclviny)\ **Post date:** [March 26, 2005, 11:54am UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/1 "2005-03-26T11:54:02Z")
Folks, Please help this mathematically slow D’ohper, I am trying to work out the percentage of my land and here are the numbers: Total land area 268,581 square miles. My property 1.490 Acres. So what percentage of the state do I own? Thanks Unclviny ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [March 26, 2005, 12:05pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/2 "2005-03-26T12:05:07Z")
0.00000086682416105383478354760761185639% ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [March 26, 2005, 12:06pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/3 "2005-03-26T12:06:38Z")
The total area is 171,891,840 acres (640 to the square mile). Back to my surveying days. ---
**Author:** ![unclviny](https://avatars.discourse-cdn.com/v4/letter/u/e274bd/32.png) [@unclviny](https://boards.straightdope.com/u/unclviny)\ **Post date:** [March 26, 2005, 12:22pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/4 "2005-03-26T12:22:12Z")
Eleven minutes this early in the morning is AMAZING!, thank you. Uncllviny ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [March 26, 2005, 2:02pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/5 "2005-03-26T14:02:00Z")
> [@don't ask](#): > > The total area is 171,891,840 acres (640 to the square mile). Back to my surveying days. Ah but, there is always some nit picking SOB, isn’t there? Since land surveying uses the methods out plane geometry and the earth isn’t a plane surface all square miles aren’t equal. Isn’t it true that out near the edges of the survey from a particular baseline and meridian a square mile isn’t really 5280[sup]2[/sup] square feet? And if that’s true then the number 171,891,840 isn’t really accurate to that many places. Just a little monkey wrench tssed into the mix. ---
**Author:** ![unclviny](https://avatars.discourse-cdn.com/v4/letter/u/e274bd/32.png) [@unclviny](https://boards.straightdope.com/u/unclviny)\ **Post date:** [March 26, 2005, 4:03pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/6 "2005-03-26T16:03:00Z")
Thanks **Don’t ask** , Thanks for the name, forever it shall be known as the 0.00000086682416105383478354760761185639% ranch Unclviny ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [March 26, 2005, 5:35pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/7 "2005-03-26T17:35:26Z")
> [@David Simmons](#): > > Ah but, there is always some nit picking SOB, isn’t there? … [The] number 171,891,840 isn’t really accurate to that many places. > > Just a little monkey wrench tssed into the mix. Not to mention that both areas, even if they’re accurately measured, are only precise to so many digits. Assuming the final zero in your property’s area (“1.490 acres”) is truly a significant digit, the result of the division should only be given to four significant digits. I’d therefore drop everything after the “…8668”. ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [March 26, 2005, 7:54pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/8 "2005-03-26T19:54:08Z")
Gee, you can always go to my site [www.1728.com/convarea.htm](http://www.1728.com/convarea.htm) for _all_ your area conversion needs. Also, the UltraConverter is quite good [www.1728.com/convert.htm](http://www.1728.com/convert.htm) **Bytegeist and David Simmons** raise some valid points about significant figures. That percentage 0.00000086682416105383478354760761185639% consists of 32 digits _implying_ it has an accuracy of 1 part in 87 million trillion trillion. Wow - that is some fancy measuring job !!! If you were to measure the Earth’s surface area to that accuracy, you would be “off” by about ± one _trillionth_ of a square millimeter. (Others are welcome to recheck my calculations). ---
**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\ **Post date:** [March 26, 2005, 10:58pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/9 "2005-03-26T22:58:56Z")
> [@David Simmons](#): > > Ah but, there is always some nit picking SOB, isn’t there? Since land surveying uses the methods out plane geometry and the earth isn’t a plane surface all square miles aren’t equal. It’s probably not a significant difference, but without knowing the error in the initial measurement, it’s tough to say. ---
**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\ **Post date:** [March 26, 2005, 11:44pm UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/10 "2005-03-26T23:44:08Z")
Assuming for a minute that Texas is roughly circular–and that’s probably good enough for our work here–and that the area given above assume it’s a plane, the area of Texas accounting for the Earth’s curvature is roughly 268,603 square miles. That’s not a significant difference in this problem. ---
**Author:** ![Go\_You\_Big\_Red\_Fire\_Engine](https://avatars.discourse-cdn.com/v4/letter/g/eada6e/32.png) [@Go\_You\_Big\_Red\_Fire\_Engine](https://boards.straightdope.com/u/Go_You_Big_Red_Fire_Engine)\ **Post date:** [March 27, 2005, 12:59am UTC](https://boards.straightdope.com/t/math-help-needed-not-homework/296343/11 "2005-03-27T00:59:59Z")
> [@unclviny](#): > > Eleven minutes this early in the morning is AMAZING!, thank you. > > Uncllviny **dont\_ask** is in Australia.