Simple command-line calculator

### Issue: Every now and then I need to do simple arithmetic in a command-line environment. E.G. given the following output: Disk /dev/sdb: 256GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 106MB 105MB fat32 hidden, diag 2 106MB 64.1GB 64.0GB ext4 3 64.1GB 192GB 128GB ext4 5 236GB 256GB 20.0GB linux-swap(v1) What's a simple way to calculate *on the command line* the size of the unallocated space between partition 3 and 5? ## What I've tried already: ## bc

bc
bc 1.06.95
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236-192
44
quit

where the bold above is all the stuff I need to type to do a simple 236-192 as bc 1+1 echoes File 1+1 is unavailable. ## expr expr 236 - 192 where I need to type spaces before and after the operator as expr 1+1 just echoes 1+1.