How do I divide in the Linux console?

I assume that by Linux console you mean Bash.

If X and Y are your variables, $(($X / $Y)) returns what you ask for.

In the bash shell, surround arithmetic expressions with $(( ... ))

$ echo $(( 7 / 3 ))
2

Although I think you are limited to integers.

Example of integer division using bash to divide $a by $b:

echo $((a/b))

In bash, if you don't need decimals in your division, you can do:

>echo $((5+6))
11
>echo $((10/2))
5
>echo $((10/3))
3

I still prefer using dc, which is an RPN calculator, so quick session to divide 67 by 18 with 4 digits precision would look like

>dc
4k
67
18/p
3.7222
q
>

Obviously, much more available: man dc

Better way is to use "bc", an arbitrary precision calculator.

variable=$(echo "OPTIONS; OPERATIONS" | bc)

ex:

my_var=$(echo "scale=5; $temp_var/100 + $temp_var2" | bc)

where "scale=5" is accuracy.

man bc

comes with several usage examples.

echo 5/2 | bc -l

2.50000000000000000000

this '-l' option in 'bc' allows floating results

Something else you could do using raytrace's answer. You could use the stdout of another shell call using backticks to then do some calculations. For instance I wanted to know the file size of the top 100 lines from a couple of files. The original size from wc -c is in bytes, I want to know kilobytes. Here's what I did:

echo `cat * | head -n 100 | wc -c` / 1024 | bc -l

You can use awk which is a utility/language designed for data extraction

e.g. for 1.2/3.4

>echo 1.2 3.4 | awk '{ print $2/$1 }'
0.352941

You should try to use:

echo "scale=4;$variablename/3"|bc

you can also use perl -e

perl -e 'print 67/8'

I also had the same problem. It's easy to divide integer numbers but decimal numbers are not that easy. if you have 2 numbers like 3.14 and 2.35 and divide the numbers then, the code will be Division=echo 3.14 / 2.35 | bc echo "$Division" the quotes are different. Don't be confused, it's situated just under the esc button on your keyboard. THE ONLY DIFFERENCE IS THE | bc and also here echo works as an operator for the arithmetic calculations in stead of printing. So, I had added echo "$Division" for printing the value. Let me know if it works for you. Thank you.