OK so if me dh and dd1 want to travel from Ealing (zone 3) to centre of London and maybe one or two tube journeys in the day before going back again same day, do we need a normal ticket (£4 adult £2 child) or a travel card (£6 or something)? We won't be using any other transport (bus for instance); we will be getting a boat from London eye to Tower of London but you have to pay for this anyway.
I can't see why we'd need the travelcard but am I being thick?