# Addition, Subtraction

No. of Players: | 1+ |

Type of Game: | written or spoken |

What you need: | pen & paper or nothing |

## Goal

To make a chain of words by adding or subtracting letters.

## How to play

Players select a four-letter word at random. Randomness can be approximated by opening a book to a random page and selecting the first four-letter word encountered there starting from the top left-hand corner. This word is either spoken or written down on a piece of paper shared by all players. The first player adds a letter to this word to make a new word. The second player then subtracts a letter from this new word to make yet another new word. The next player adds a letter and so on, alternating adding and subtracting letters round the players. No word can be repeated. A player who cannot make a new word drops out of the game. The last player to have successfully made a new word is the winner. Alternatively, the first player can choose to subtract a letter so that the second player must add a letter, and so on. Another game variation gives players a choice to either add or subtract letters during each turn. Players can also agree to work independently to see who can make the longest chain of words.

## Example

Alina and Bruce agree that they will have a choice whether to add or subtract letters to create a chain of new words. They randomly select CARE from a book, write this down and then flip a coin to see who gets to go first. Bruce wins the flip and adds the letter T to make CARET. Here is the chain of words they made:

CARE–CARET–CART–ART–MART–MAR–MARE–ARE–PARE–PAR–PARK–ARK–BARK–BAR–BARE

After seven rounds, Alina wins the game with BARE since neither player can make another word that has not already been made.

Did you know?

At your next get-together with friends or colleagues, you can convincingly pass yourself off as a mathematical genius. Here's how to do it.

Math Trick #1

First, select someone. Tell them to think of any number – no matter the number of digits. Advise them that if they have a large or complex number, they might need a calculator for what comes next. (Having one handy to give them is a nice touch.) Then tell them to:

Multiply the number by 3.

Add 45.

Double it.

Divide by 6.

Subtract the original number.

Then (taking your time for dramatic effect, of course) you announce the answer is 15. And they are uttery amazed that the answer is actually 15!

But what you don't tell them is that the answer is always 15 for any number you start with, as long as the mathematical operations above are exactly followed each and every time. So be sure not to repeat this trick immediately with the same people, or they will surely spot the pattern. Or else you'll need another trick up your sleeve.

For math lovers,

here's the

equation

Math Trick #2

Again, select someone and tell them to think of any number. Then have them:

Multiply it by 3.

Add 6.

Divide by 3.

Subtract the original number.

Then step back and hold up 2 fingers. Because the answer (everytime with these steps) is 2!

That's all it takes. Just memorize the steps and answers to these two simple tricks, and you'll be a math superstar at your next party!

Here's the

equation