I have created a Parent List that has a multiple selection checkbox for "Media Type". If a user chooses multiple media types, I want user to add a quantity to each media type selected. I am using SharePoint 2010. I am a novice so I am somewhat limited to SPD, InfoPath and using "simple" code of the brilliant SP developers from internet searches. Assistance is appreciated.
Out-of-the-box having such behavior is not offered by any component. You could however opt for:
In both cases, you should probably create additional columns for each quantity you need to store per record.