Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
ZeroDivisionError: float division by zero

#!/bin/sh

total=137
linux_and_steamos=56
echo "${linux_and_steamos}/${total}*100" | bc -l

annelin@nevermore ~ » time ./igor.sh 
40.87591240875912408700

real	0m0.002s
user	0m0.000s
sys	0m0.002s
annelin@nevermore ~ » time ./igor.js 
40.87591240875913

real	0m0.038s
user	0m0.034s
sys	0m0.005s

annelin@nevermore ~ » cat igor.sh 
#!/bin/bash

round()
{
echo $(printf %.$2f $(echo "scale=$2;(((10^$2)*$1)+0.5)/(10^$2)" | bc))
};


total=137
linux_and_steamos=56
round `echo "$linux_and_steamos/$total*100" | bc -l` 0


annelin@nevermore ~ » time ./igor.sh 
41

real	0m0.004s
user	0m0.002s
sys	0m0.002s

function math.round(value, precision)
	local mult = 10^(precision or 0)
 	return math.floor(value * mult + 0.5) / mult
end

total=137
linux=56

print(math.round(linux/total*100, 0))

annelin@nevermore ~ » time lua igor.lua 
41

real	0m0.001s
user	0m0.000s
sys	0m0.001s

echo 'scale=1;100*56/137' | bc -l
40.8

echo 'a=0.5+100*56/137;scale=0;a/1' | bc -l 
41

dc -e '1 k 100 56 * 137 / 0.5 + 0 k 1 / p' 
41

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

void usage(const char *name, int rc) {
    fprintf(stderr, "%s [total] [steamos+linux]\n", name);
    exit(rc);
}

int main(int argc, char *argv[]) {
    if (argc < 3) {
        usage(argv[0], EXIT_FAILURE);
    }

    long all = atol(argv[1]);
    long steamos = atol(argv[2]);

    if (all != 0) {
        long part = (long)round((double)steamos / all * 100);
        printf("%ld\n", part);
    } else {
        puts("N/A");
    }

    return EXIT_SUCCESS;
}

$ gcc -std=c99 -Wall -Wextra -pedantic -O3 math.c -o c_math -lm
$ time ./c_math 137 56
41

real    0m0.002s
user    0m0.000s
sys     0m0.000s

perl -e 'printf "%.0f\n", 56 / 137 * 100
41

function math.round(value, precision)
	local mult = 10^(precision or 0)
 	return math.floor(value * mult + 0.5) / mult
end

function usage()
	io.stderr:write("./test.lua <total> <steamos+linux>\n")
	os.exit()
end

-- argv --
if #arg < 2 then usage() end
-- main --
local all = tonumber(arg[1])
local steamos = tonumber(arg[2])
local result = 'N/A'

if all ~= 0 then result = math.round(steamos/all*100, 0) end
print(result)

annelin@nevermore ~ » time lua test.lua 137 56
41

real	0m0.001s
user	0m0.000s
sys	0m0.001s

time for i in {1..1001} ; do ./c_math 137 56 >/dev/null ; done

real    0m0.756s
user    0m0.068s
sys     0m0.188s

annelin@nevermore ~ » time for i in {1..1001}; do lua test.lua 137 56 > /dev/null; done

real	0m0.967s
user	0m0.331s
sys	0m0.689s

$ time ./games 
Ratio 41%

real    0m0.002s
user    0m0.000s
sys     0m0.000s

$ time ./games -games 0 -steam 0
Ratio NaN%

real    0m0.001s
user    0m0.004s
sys     0m0.000s

Python 3.4.3 (default, Mar 25 2015, 17:13:50) 
[GCC 4.9.2 20150304 (prerelease)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> linux = 29
>>> all = 81
>>> linux/all
0.35802469135802467
>>>