Code Check for Disk Freespace

Question

Hello, 
I have a very basic Powershell command string working, but when I execute it I get an error that says "Attempted to divide by zero".  When doing the math I am not attempting to divide by zero, so even though the commands work, I was wondering
if anyone could explain to me why that error pops up. 
Thank you!
Get-WmiObject win32_logicaldisk | where-object {$_.Freespace -ge ((($_.freespace/$_.size) * 100)
) -and $_.drivetype -eq 3}

Answer 1

Hello jrv, 
Actually, the arithmetic does work.  The problem is that I was trying to filter the drivetype in the where-object instead of with the filter as you suggested.  As soon as I switched that around my where-object and my formula worked just fine. I
don't appreciate your snide and unnecessary comment at the end about skipping class in the second grade and if I could report it as abuse I would.  I am trying to learn powershell as a beginner and people like you make asking questions difficult. 
How about you try helping others instead of putting them down?
As I poited out - elementarty school arithmetic.  The math does NOT work in any kind of usefule fashion.
Look closely at the numbers and you will see what I mean.
(($_.freespace/$_.size) * 100)
This is always 100 time the freespace reading,  T^hat makes "Fre4esapce equal to 1/100 of this number or 1%.
$_.Freespace -ge ((($_.freespace/$_.size) * 10o
if freespace is 10 and size is 100 then the numerbs are (10 -ge  ((10/100) * 100)
Factor out10.
(1 -ge  ((1/10) * 10)
1/10 * 10 will always be 1.
You are in eff3ect saying is 1 greater than or equal to 1 which will always be true.
The test is pointless and does not check for a freespace threshold.
We want here to see the percentage of free space.  Percentage is a ration of two numbers.
Freespace/Size is a ration (third grade arithmetic - if I have three cookies and I give one to you what fr4action did I keep?
if freespace ia1 25 GB and Size is 250Gb then the ratio p(unnormalized percentage) is 23/250 or 1/10 or .10000000 TO kae this a human percentage with a % sign we multiply by 100. .1 * 100 is .... 10 and then add the sign for 10&.
The frespace (%) for a dis is (freesapce/size) * 100 if expressed as a percent.
?{($_.freespace/$_.size * 100 -lt 10}
This would filter out and show all drive that have less than 10% freespace.
It is easier to just say this:
?{($_.freespace/$_.size -lt .1}
Since the ratio will alwys be a number less than '1'.
Too many techs including many with college degrees get this wrong because they forgot what they learned bout apples and pies in elementary school.
Don't feel bad. You are in good company.  Most of Congress cannot add or do ratios either.
¯\_(ツ)_/¯