buying one day travel pass or three day travel pass?

i am going to shanghai and hangzhou for one week, the first two day in SH and follow by three days in hangzhou then two more days in SH, would u suggest me to buy a one day travel pass for every day in SH or a three day travel pass?can the three day travel pass use for first two days and continue use for another one day?what is the current cost for both one day and three day travel pass?Thank you^^