At lunch start singing the happy birthday song with you are one or two of your friends and see how many people you don't even know join in.
Go To Your Friends house, Put Flour On The Fan And Turn On The Fan When They Walk In The Room :).
Go on your friends phone and download apps that spell something and watch their reaction!
Get a group of friends and assign them all a roll (mom, dad, son, uncle) and see how long they go with it.
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