**We all make thousands of choices everyday. However, our decisions are affected by a number of factors; from our health to our wealth.**

**Yet it is possible to predict some decisions. For example, if one asks an individual to choose a card from a standard deck then it is very difficult to determine which card the individual may have chosen. In fact, with 52 cards in a deck, the chances of correctly naming a volunteer’s chosen card in less than 2%.**

**However, it has been observed that certain ‘personality types’ will tend to group the same sort of cards together. This means that, if an individual is asked to choose five cards, then it is possible to determine one of those cards from the other four. Although this doesn’t always work, it has been shown that the chances do increase to over 63%, despite the fact that there are over 2.5 million ways of choosing 5 cards from a pack of 52.**

*Now ignore everything above, as it was obviously bunk.*

This is a mathematical card trick where your phone acts as your assistant and uses the volunteer’s chosen cards to send you a secret message.

After the volunteer finishes their selection you will see four visible cards and one hidden card.

The suit of the card in the first position tells you the suit of the hidden card.

The remaining three cards are assigned numerically as Low, Medium and High such that;

LMH = 1

LHM = 2

MLH = 3

MHL = 4

HLM = 5

HML = 6

Add this value to the card in the first position to give you the value of the hidden card. Here, cards wrap around from King to Ace.

For example, if the app displays:

Queen Spades, 7 Hearts, 10 Spades, 5 Clubs;

then the fifth card was the 3 of Spades.

If two cards have the same numerical value then the suits are arranged from low to high in order Clubs, Hearts, Spades, Diamonds – or CHaSeD for short.

For example, if the app displays:

3 Clubs, 5 Hearts, 5 Clubs, Ace Hearts;

then the fifth card was the 9 of Clubs.

*Use the app itself to practise this secret code.*

To perform this with a real deck of cards you will need an assistant.

If the volunteer picks five cards, at least two of them must be the same suit. From the five chosen cards your assistant picks two of the same suit.

If the difference between the values of the two cards is 6 or less then your assistant hides the higher card.

If the difference between the values of the two cards is greater than 6 then your assistant hides the lower card.

Your assistant places the other card in the first position, then arranges the remaining three cards to encode the number required to be added to the first card.

*This five card trick is usually credited to the mathematician and magician William Fitch Cheney, Jr.*