Fiona finds 1 shell on her first day at the beach. every day that wek she finds twice as many shells as she did the day before. hiw many shells does Fiona find on the seventh day?

Ok, so on the first day she finds one, the second she finds two, the third four, the fourth eight, the fifth sixteen, the sixth thirty two, and the seventh sixty four. The answer is 64

She finds 64 shells on her seventh day, 1=1 2=2 3=4 4=8 5=16 6=32 7=64