or download this
perl -e '$num=12314212412124124124.10623;print "initial:\t$num\n";prin
+tf ("formatted:\t%f\n",$num);printf ("rounded:\t%.2f\n",$num);'
initial: 1.23142124121241e+19
formatted: 12314212412124123136.000000
rounded: 12314212412124123136.00