If you want to calculate the sum volume of 3d solids you can use 'paste Total Volume'. Select the 3d solids you want and hit enter. The sum volume is shown in an alert and a prompt on the command line. The command places the result on the windows clipboard as well. So if you want to write the result somewhere, for instance in an email or excel document you only have to click on the place where the result should go and you can paste the result straight away.