Non-integer calculation in Shell

use bc for this:
example:

#!/bin/bash
# Linux Shell Scripting Tutorial 1.05r3, Summer-2002
# Written by Vivek G. Gite 
# Latest version can be found at http://www.nixcraft.com/
# Q10
a=5.66
b=8.67
c=`echo $a + $b | bc`
echo "$a + $b = $c"
# ./ch.sh: vivek-tech.com to nixcraft.com referance converted using this tool
# See the tool at http://www.nixcraft.com/uniqlinuxfeatures/tools/

Also, to run a loop of jobs, use the command "wait" to wait until the previous job finishes.( you need to run the job in background using "&")