Datagridview moves to first column when user arrows down after editing

I have a datagridview that lists a bunch of information. In the 8th column is a quantity column. What I'd like is for the user to be able to enter the quantity for the first item, arrow down on the keyboard and enter the quantity for the second item and so on. They can currently arrow down the 8th column. However, as soon as they enter a quantity in one of the columns and that row goes into edit mode, arrowing down ends the edit operation and the curser is moved back to the first column. How do I prevent the curser from moving back to column 1? It is very annoying to my users and stunting their productivity.