## Class Presentation Topics |
||

EGYPTIAN
Egyptian mathematics |
The Egyptians used hieroglyphic symbols for their numerals. They had no zero, so it is not a true base ten system. | |

BABYLONIAN
Why base 60? Babylonian numbers Babylonian mathematics |
Base 60 is useful because so many numbers divide into 60. | |

DUODECIMAL
Base 12 Dozenal society |
Base 12 is a favorite because it is easily divisible by many factors. The system still lingers today in our 12 hours, 12 months, 12 inches per foot, 12 eggs per dozen, etc. | |

INCAN
Quipu Ask Dr. Math |
The Incans used a line of knotted strings to keep records of inventories. The size, color, and length of each string/knot were important. | |

CHINESE
CHARACTER SYSTEM Tiffany |
The Chinese use characters for their numerals. They also have two different number systems, one for the general usage and a formal one for banking. | |

STICK MATH or NUMERAL
RODS Counting rods Another link |
Asian cultures adopted this method before the abacus. | |

YORUBAN
Yoruban system Another link |
The Yoruban people of Nigeria use a combination of base 5/base 20. Their system is based on counting cowrie shells. | |

The Mayans were some of the first to use zero. | ||

BINARY Birthday cards Base 2 Binary fingers |
Computers only deal with the numerals zero and one, which correspond to ON or OFF. | |

ROMAN Roman numerals |
You should be glad we don't use this system today! | |

HEXIDECIMAL Base 16 |
Base 16 for computers is also related to the binary system. | |

HAWAIIAN |
Based on counting fours |

Ethnomathematics

Other
counting methods

More
number system links

Alien
number system

Base
four "dog" math