In this case, we are dividing the value of the variable for a given number and reassigning the new value to it:

zarrelli@:~$ ./userreassign-division.sh 
Hello user, please give me a number: 
10
And now another one, please: 
2
The user_input variable value is: 10
The adding variable value is: 2
10 divided for 2 is: 5
And the user_input variable has now the value of 5
But the adding variable has still the value of 2