Two Sheet Calculation/Summary

Hi -

I am in need of some assistance. I have pretty good basic Excel skills, but I'm at a loss for how to do something I need to do.

I've attached my spreadsheet for a fundraiser our school program is doing.
I have a Summary sheet and a Detail Sheet.

You can probably figure out what I'm trying to do by looking at the spreadsheets, but just for clarification - I'm trying to summarize by student name the number of each size poinsettia ordered. That detail by order is on the Detail page. Some students will have one order, others several more then 1.

I just can't figure out how to do it and am hoping someone can just show me the way!

Thanks,
Mary