Note that while $((010)) is required by POSIX to expand to 8, several shells don't do it by default (or only in some contexts) unless in a conformance mode as that's a feature you usually do not want.
With zsh, that's controlled by the nooctalzeroesoctalzeroes option (off by default except in sh/ksh emulation).
$ zsh -c 'echo $((010))'
10
$ zsh -o octalzeroes -c 'echo $((010))'
8
$ (exec -a sh zsh -c 'echo "$((010))"')
8
In mksh, that's controlled by the posix option (off by default):
$ mksh -c 'echo "$((010))"'
10
$ mksh -o posix -c 'echo "$((010))"'
8
In bash, there's no option to turn it off, but you can use the $((10#010)) ksh syntax to force interpretation in decimal (also works in ksh and zsh), though in bash and mksh -o posix, $((10#-010)) doesn't work (treated as 10#0 - 010 as you can see from the expansion of $((-10#-010)) yielding -8), you need $((-10#010)) (or $((- 10#010)) for compatibility with zsh which complains about -10 being an invalid base).
$ bash -c 'echo "$((10#010))"'
10
With ksh93, compare:
$ ksh93 -c 'echo "$((010))"'
8
$ ksh93 -c '((a = 010)); echo "$a"'
8
with:
$ ksh93 -c 'a=010; echo "$((a))"'
10
$ ksh93 -c 'printf "%d\n" 010'
10
$ ksh93 -c 'let a=010; echo "$a"'
10
$ ksh93 -c 'echo "$((010e0))"'
10
$ ksh93 -o letoctal -c 'let a=010; echo "$a"'
8
So at least if you're coding for any of those shells specifically, there are ways to work around that "misfeature".
But none of those would help when writing a POSIX portable script, in which case, you'd want to strip the leading zeros as you have shown.
