It’s very likely he was in Hawaii between school years. It’s normal for kids to go home in the summer (or it was back then). What else was he supposed to do? Besides, being back with the ol’ Choom Gang in Hawaii living off his grandparents is a whole lot better than hanging around a half empty campus. Getting a scholarship doesn’t mean he was poor. They give away scholarships like candy for being left handed to skin color to being a foreigner. The Dunhams had money. He didn’t have to work. All that stuff about him being raised poor and on welfare is nothing but bunk. IIRC, after all that talk about finally paying off students loans was proved another lie because it wasn’t on their 1040s.
This article says he stayed in Southern Cal for summer...
http://www.cbsnews.com/2100-250_162-4101069.html
“Thummalapally lived with Obama the summer of 1980. The two ran together daily, three miles in the early morning, often chatting about their dreams. Thummalapally wanted to start a business back home; Obama talked about helping people.”