Not enough sleep or disruptions to the sleep-wake cycle (such as those that may occur with shift work or travelling to a different time zone) cause the physiological state known as fatigue. Staying awake for 24 hours leads to a reduced hand-to-eye coordination that is similar to having a blood alcohol content of 0.1.
There are 13 hearts in a standard 52 card deck. There are also 13 diamonds, 13 spades and 13 clubs.
Starting from the right, place one card at a time to the center: ace-of-heart, ace-of-spade, two-of-hearts, two-of-spades, etc. Then cut the deck when finished exactly 5 cards from the top to the right and 5 cards to the left. Repeat several times and the deck will revert to the original order. Sleight-of-Hand: