Fizz buzz

Fizz buzz is a group word game for children to teach them about division. Players take turns to count incrementally, replacing any number divisible by three with the word "fizz", and any number divisible by five with the word "buzz".

Play

Players generally sit in a circle. The player designated to go first says the number "1", and each player thenceforth counts one number in turn. However, any number divisible by three is replaced by the word fizz and any divisible by five by the word buzz. Numbers divisible by both become fizz buzz. A player who hesitates or makes a mistake is eliminated from the game.

For example, a typical round of fizz buzz would start as follows:

1, 2, Fizz, 4, Buzz, Fizz, 7, 8, Fizz, Buzz, 11, Fizz, 13, 14, Fizz Buzz, 16, 17, Fizz, 19, Buzz, Fizz, 22, 23, Fizz, Buzz, 26, Fizz, 28, 29, Fizz Buzz, 31, 32, Fizz, 34, Buzz, Fizz, ...

Variations

Different divisors can be used in place of, or in addition to, 3 and 5, and different words or gestures can replace "fizz" or "buzz". For example, in Australia a variant based on the game of cricket is played. In this variant, the special numbers are 4 and 6, which are replaced with the cricket umpiring gestures for their respective scoring plays. A common version of the game is also called "7 Boom". The players replace every number divisible by 7 or containing the digit 7 with "boom".

Instead of replacing numbers that have 3 or 5 as a factor, the game can be played by replacing numbers containing the digit 3 or 5 with "fizz" or "buzz".

1, 2, Fizz, 4, Buzz, 6, 7, 8, 9, 10, 11, 12, Fizz, 14, Buzz, 16, 17, 18, 19, 20, 21, 22, Fizz, 24, Buzz, 26, 27, 28, 29, Fizz, Fizz, Fizz, Fizz, Fizz, Fizz Buzz, Fizz, Fizz, Fizz, Fizz, 40, 41, 42, Fizz, 44, Buzz, ...

In these variations, sometimes only the actual digit is replaced, so 23 becomes "twenty-fizz" and 50 is "buzzty". This variation can be combined with the original to form an even more challenging sequence:

1, 2, Fizz, 4, Buzz, Fizz, 7, 8, Fizz, Buzz, 11, Fizz, Fizz, 14, Fizz Buzz, 16, 17, Fizz, 19, Buzz, Fizz, 22, Fizz, Fizz, Buzz, 26, Fizz, 28, 29, Fizz Buzz, Fizz, Fizz, Fizz, Fizz, Fizz, Fizz Buzz, Fizz, Fizz, Fizz, Fizz, Buzz, 41, Fizz, Fizz, 44, Fizz Buzz, ...

The game can be played in a mathematical base other than 10. For example, playing in base 5 would proceed as follows:

1, 2, Fizz, 4, Buzz, Fizz, 12, 13, Fizz, Buzz, 21, Fizz, 23, 24, Fizz Buzz, 31, 32, Fizz, 34, Buzz, Fizz, ...

More challenging variation has the direction of play change on Fizz or Buzz, but not on Fizz-Buzz. For certain sequences, this makes the action bounce between 2 or 3 players and causes misplays when it breaks out. The 3/7 version of the game has a complex sequence between 12 and 18, for example. A New Jersey variation is just to say buzz on prime numbers and switch directions. The reversal of direction may be optional.

Fizz Buzz Woof

One variation has expanded to such an extent as to have its own related name. Many of the above rules are the same. In this case, the number 3 becomes Fizz, 5 becomes Buzz, and 7 becomes Woof. The main rules in this game are that any number that contains the number or is divisible by that number is replaced by an occurrence of the word. If the number has 2 instances of that number (i.e. 33 or 55) and is divisible by that number, then the word is said three times in this example. The additional rule is that the words (if more than one occur) must be said in the order given in the title. For example:

1, 2, Fizz Fizz (3), 4, Buzz Buzz (5), Fizz (6), Woof Woof (7), 8, Fizz (9), Buzz (10), 11, Fizz (12), Fizz (13), Woof (14), Fizz Buzz Buzz (15), 16, Woof (17), Fizz (18), 19, Buzz (20), Fizz Woof (21), 22, Fizz (23), Fizz (24), Buzz Buzz (25), 26, Fizz Woof (27), Woof (28), 29, Fizz Fizz Buzz (30), Fizz (31), Fizz (32), Fizz Fizz Fizz (33), ...

Other uses

Programming interviews

Fizz buzz has been used as an interview screening device for computer programmers. Creating a list of the first 100 Fizz buzz numbers is a trivial problem for any would-be computer programmer, so interviewers can easily sort out those with insufficient programming ability. FizzBuzz is also a popular Kata in the software craftsmanship movement. Computer programmers who call themselves "Software Craftsmen" will use exercises, often similar to this one, called 'Kata' repeatedly, often daily, in order to practice their craft, much like a soldier, a musician, a doctor or a dancer would repeat exercises or movements to practice theirs. The following code is an example implementation using JavaScript:

for (var i = 1; i <= 100; i++) {
    // For each iteration,
    // initialize an empty string
    var string = ''; 

    // If `i` is divisible by 3
    // with no remainder, append `Fizz`
    if (i % 3 === 0) {
        string += 'Fizz';
    }

    // If `i` is divisible by 5
    // with no remainder, append `Buzz`
    if (i % 5 === 0) {
        string += 'Buzz';
    }

    // If `string` is still empty,
    // `i` is not divisible by 3 or 5,
    // so use the number instead.
    if (string === '') {
        string += i;
    }

    // At the end of each iteration, 
    // print the string to the screen.
    console.log(string);
}

Drinking games

Adults may play Fizz buzz as a drinking game, where making a mistake leads to the player having to make a drinking-related forfeit.

External links

• Dr Mike's Math Games For Kids - Fizz Buzz
• About.com: Bizz Buzz- The Drinking Thinking Game
• FizzBuzz on Rosetta Code
• Code Kata FizzBuzz - Test Driven Development In Ruby