Formula for a range between two variables in one cell

I am making a packing list for my company and we want to number the cartons on the excel sheet. We number the cartons as a range e.g 001 - 005 which means the product is packed in 5 cartons, numbers 1 to 5. The next product has 2 cartons so the range would be 006 - 007. I want a method that allows my staff to input the quantity of cartons for each product and excel automates the numbering. The staff would write "2" in the cells E$10-E16 (or another hidden column, that's fine) and excel would input 001 - 002. In the next product column, they'd write "5" and excel would input 003 - 007.

The second part of my question is: we also write the CBM (cubic meter) of the carton on the sheet, I'd like the staff to input a value in H2 and that value be multiplied by the "CTN number" in the same row E2 and the result to be input in the same CBM cell the staff wrote in (cell H2). How would I go about doing this? I prefer to use as few columns as possible and as few hidden columns as possible in order to avoid confusion as we're printing on A4, but I would like to hear all ideas you guys have :D

Thank you in advance for the help