Multiplication/addition function

[Trixie]

I obviously know less about functions than I thought I did. I've got the attached spreadsheet set up except getting totals at the bottom. The production total L44, would be column A multiplied by the quantity entered in columns L and summed. Same for Total SF, square footage in column B times quantity in L and summed at the bottom. This would continue daily, needing sums under each column. I had a real mess going... Any help would be appreciated.