The symbols for the numbers 0 to 11 on this site are:

0 1 2 3 4 5 6 7 8 9 X E

Base 10 | Base 12 | |

1/2 | 0.5 | 0;6 |

1/3 | 0.(3) | 0;4 |

1/4 | 0.25 | 0;3 |

1/5 | 0.2 | 0;(2497) |

1/6 | 0.1(6) | 0;2 |

1/7 | 0.(142857) | 0;(186X35) |

1/8 | 0.125 | 0;16 |

1/9 | 0.(1) | 0;14 |

1/10 | 0.1 | 0;1(2497) |

1/11 | 0.(09) | 0;(1) |

1/12 | 0.08(3) | 0;1 |

Base 10 | Base 12 | |

2 | Ends in 0,2,4,6,8 | Ends in 0,2,4,6,8,X |

3 | Digit sum divisible by 3 | Ends in 0,3,6,9 |

4 | Last two digits divisible by 4 | Ends in 0,4,8 |

5 | Ends in 0,5 | Subtract first or last two digits from rest |

6 | Divisible by 2 and 3 | Ends in 0,6 |

7 | Subtract last digit twice from rest | Add last digit three times to rest |

8 | Last three digits divisible by 8 | Last two digits divisible by 8 |

9 | Digit sum divisible by 9 | Last two digits divisible by 9 |

10 | Ends in 0 | Divisible by 2 and 5 |

11 | (Odd digits - even digits) divisible by 11 | Digit sum divisible by E |

12 | Divisible by 3 and 4 | Ends in 0 |

One of the methods might be unfamiliar. The method in base 10 to check divisibility by 7 works like this. Take the last digit, double it, and subtract it from the rest of the number. If this is divisible by 7 then the original number is. An example:

Is 178444 divisible by 7?

17844 - 2*4 = 17836

1783 - 2*6 = 1771

177 - 2*1 = 175

17 - 2*5 = 7 => yes

Similar in dozenal. 178444 = **87324**

Is **87324** divisible by **7**?
**8732 + 3*4 = 8742
874 + 3*2 = 87X
87 + 3*X = E1
E + 3*1 = 12** = 14 => yes

The same test for division by 5 in dozenal:

Is **87324** divisible by **5**?
**873 - 24 = 84E
4E - 8 = 43** = 51 => no

Perfect squares in base 12 end in

H:MM:SSYour current time is calculated here:

1

Other length units are defined by using standard metric prefixes. A
dozenal inch or decifoot is 1/12 f: 1**df** ~ 2.0174 cm. A dozenal
mile is 1**kf** ~ 418.33 m.

The unit of velocity is 1**f**/**s** = 0.697 m/s = 2.51 km/h

Wind scale = 12 *

Scale | Velocity | Beaufort | Hurricane |

0;0 | 8.7 km/h | 2 | |

2;0 | 13.2 km/h | 3 | |

4;0 | 19.9 km/h | 4 | |

6;0 | 30.1 km/h | 5 | |

8;0 | 45.6 km/h | 6 | |

9;0 | 56.1 km/h | 7 | |

X;0 | 69.0 km/h | 8 | |

E;0 | 84.8 km/h | 9 | |

10;0 | 104.3 km/h | 11 | |

11;0 | 128.2 km/h | 12 | 1 |

12;0 | 157.9 km/h | 12 | 2 |

13;0 | 194.2 km/h | 12 | 3 |

14;0 | 238.9 km/h | 12 | 4 |

15;0 | 293.8 km/h | 12 | 5 |

1 | 1 | 1 | |

1/2 | 1/2 | ||

4 | |||

1/4 | |||

2 | 2 | ||

1 | 1 | 1 |

The first of these methods looks most like the American Dollar system, the last of these methods looks more of the European system for the Euro. The only difference is that the "big" step is 3 units and not 2 1/2 units. As is shown by the Dutch 3 guilder coin from 1830 a base 12 currency system has been in use in the past on the continent as well as in Britain with its old pence / shillings system.

π = **3;18480 9493E 91866 4573X 6211E E1515 51X05 72929 0X780 9X492 ...**

Great Britain Dozenal Society

Dozens Online Forum