Ilusionary Card Trick

first u take all the cards (52cards) then u put 26 cards on the floor showing everybody then u have to remember the 7th card in ur 26 cards.After u put all 26 cards take then and put them in bottom of the rest of the cards.then from top u put one card and for example if ur card is 5 u put 5 cards down.i mean u have to count up to more example if u get a 10 Q K J then u dont put any cards because they equals to 10.u do it 4 times then u count all the cards u tell the audience that i will get whatever ur 7th card was in what ever ur all cards counts up to.try it as many times before showing it to anybody.