sh-3.1$ cat script.sh 
#!/bin/bash
for i in `seq 1 100`;
        do
               echo $(($(tail -n1 testdatenbla.text) + 1)) >> testdatenbla.text
        done   
sh-3.1$ cat super.sh 
#!/bin/sh
#super.sh
echo "1" > testdatenbla.text
sleep 1
echo starte script1
script.sh &
echo starte script2
script.sh &
sleep 6
cat testdatenbla.text