Improve doc about GiB vs GB

docs/source/configuration-setup.rst

@@ -50,20 +50,19 @@ string, like "100 GB".
 Gigabyte vs Gibibyte
 ~~~~~~~~~~~~~~~~~~~~
 
-It is important to note that Dask makes the difference between 
-power of 2 and power of 10 when specifying memory. This means that:
+Dask makes the difference between GB (gigabyte) and GiB (gibibyte):
+
 - 1GB = :math:`10^9` bytes
-- 1GiB = :math:`2^{30}` bytes
+- 1GiB = :math:`2^{30} = 1024^{3}` bytes :math:`\approx 1.074` GB
 
 ``memory`` configuration is interpreted by Dask memory parser, and for most
-JobQueueCluster implementation translated as a resource requirement for job 
-submission. 
-But most job schedulers (this is the case with PBS and Slurm at least) uses
-KB or GB, but mean KiB or GiB. Dask jobqueue takes that into account, so you
-may not find the amount of memory you were expecting when querying your job
-queuing system. To give an example, with PBSCluster, if you specify '20GB' for
-the ``memory`` kwarg, you will end up with a request for 19GB on PBS side. 
-This is because 20GB ~= 18.6GiB, which is rounded up.
+JobQueueCluster implementation translated as a resource requirement for job
+submission. But most job schedulers (this is the case with PBS and Slurm at
+least) uses KB or GB, but mean KiB or GiB. Dask jobqueue takes that into
+account, so you may not find the amount of memory you were expecting when
+querying your job queuing system. To give an example, with PBSCluster, if you
+specify ``memory='20GB'`` you will end up with a request for 19GB on PBS side.
+This is because 20GB :math:`\approx` 18.6GiB, which is rounded up.
 
 This can be avoided by always using 'GiB' in dask-jobqueue configuration.