In my local Tesco there was a sign on the end of an aisle where they had a load of kids products called Goodness. All you have to do is buy 2 of the products and you can claim a free kids ticket to a number of zoos/wildlife parks etc.
I had to put in some details from my receipt but now am taking DD to Chessington free!
Thought it was too good to be true but it isn't as I emailed them to check.Kids only go free with a full paying adult but I spent £3.48 on stuff DD will eat and got a ticket worth £28!!!!