January 22, 2009 “Whether you think you can or can’t, you’re right.” -Henry Ford

January 22, 2009 Sec 2.3: Numeration (know: Roman, Babylonian & Mayan be able to use Egyptian) Exploration 2.8

2.3 (cont’d) Roman system ValueSymbolValueSymbol 1I100C 5V500D 10X1000M 50L

2.3 (cont’d) Egyptian system 1 =(staff)10,000 = (pointing finger) 10 = (heel bone) 100,000 = (fish or tadpole) 100 =(scroll)1,000,000= (astonished person) 1000 = (lotus flower)

2.3 (cont’d) Babylonian system ValueSymbol 1  10  Positional system The number 60 Symbol for zero: (developed later) Reason we have 60 minutes in an hour!

2.3 (cont’d) Mayan system The number 20 Used the concept of zero, but only for place holders Used three symbols: 150 Wrote their numbers vertically: is = 10, is = 14

2.3 (Mayan system cont’d) Mayans left a vertical gap to represent place value: is one 20, and 0 ones = 20. is two 20’s + 6 = 46

2.3 (cont’d) Write the following numbers in Roman, Egyptian, Babylonian and Mayan numbers:

2.3 (cont’d) Answers: Hindu- Arabic RomanEgyptianBabylonianMayan 8:VIII||||||||   49:IL ∩∩∩∩ |||||||||     111:CXI ∩ |   

2.3 (cont’d) What similarities/differences do you see in these systems? Advantages/disadvantages of each system?

Exploration 2.8 (Alphabitia) Read the introduction and Part 1 Use the “artifacts” and work on Part 1 as a group. Work on Part 2 #1 as a group, once you are all comfortable with your system. The poster is part of your homework for Tuesday. (exchange contact information with your group)

Homework Read textbook section 1.7 & pgs 101 – 108 Do the textbook problems listed online Finish the Alphabitia table you started in class; as a group, create a poster as outlined in the Explorations book. We will continue Exploration 2.8 on Tuesday.