What happens to --max-load if N is integer and not float?

[PATTON, BILLY \(SBCSI\)]

I have supplied some convenience scripts for the users.
Here is an test case without calling make.

#!/usr/bin/ksh

max=`ioscan -fnkC processor | grep -c processor`
if [ $max -le 1 ] ; then
  max=1.0
else
  let max=$max-0.5
fi

echo "gmake -j --max-load $max"

If integer here is a problem, do you know how to convert it to a float?