Have you tried the find command with execution ?
find
My sample will echo the files, but you can call a shell script with the filename as a parameter
find . -maxdepth 1 -type f -exec echo {} \;
A simple for loop in the shell:
for file in *; do sh Calculate.sh "$file"; done
find . -maxdepth 1 -type f | xargs -n 1 -I % Calculate.sh %