The division operator performs numeric division:

20 / 5 

An error will be thrown if an attempt to divide by 0 is made:

PS> 1 / 0
Attempted to divide by zero.
At line:1 char:1
+ 1 / 0
+ ~~~~~
    + CategoryInfo : NotSpecified: (:) [], RuntimeException
    + FullyQualifiedErrorId : RuntimeException 

Division using negative numbers is permitted in PowerShell. When a positive number is divided by a negative number, the result will be negative.