I have an Android SmartPone and it has 64 GB of Internal Memory.

I got a SD Card with 256 GB of Memory.

I put it into the Phone and let the Phone Format it.

I selected Shared Memory option.

I put some Files on my Phone and looked at the Icon for my Phone in My Computer on Win10 and it says Internal Shared 37.6 GB of 48.0 GB what is this?

Should it not say 37.6 GB of 256 GB what am I not understanding?

Then I go into my Phones Settings under Storage and it says 10% used 289 GB Free.

I am not understanding this at all.

 

There are discrepancies that arise from the difference between:

1. 1KB = 1,000
2. 1 KiB = 1,024

These differences get larger as we go to larger memories.
https://en.wikipedia.org/wiki/Kilobyte

 

I'm no Android expert but you may have to enable sharing of the SD card in the Android OS. Otherwise it may be "hidden" from your computer.
The built-in memory may be partitioned to have an untouchable area it doesn't even show you.