Day 9, MAT115

Two things, in particular:

• You are permitted a calculator, but you may not use a phone as a calculator.
• If you don't justify your answers for the test, you won't get many points.

You were to justify your answers.

One thing to think about is how to use previous numbers to get the next. Several of you did a really nice job of justifying your answers, and making imaginative leaps. We'll have a look at some of your answers first.

Then we can take a peek at this 17th century Japanese version (source)

Discussions and material covered in class are fair game. You should review the web agendas for each day.

• one-to-one correspondence (examples....)
• Body counting
• "Primitive counting"

• blocking
• prime
• positional/place value
• bases
• Babylonians
• zero
• Mayans
• Chinese
• "Fraudini" (binary, base 2)

• Fibonacci Nim
• Fibonacci numbers and rabbits (first look at fractals)
• Pascal's (Yanghui's) triangle
  • powers of 2
  • symmetry
  • counting numbers
  • triangular (and other) numbers

• Unique representation
  • as primes
  • as powers of two
  • as non-consecutive Fibonaccis

• trees as organizers

• You should recognize
  • the birthday problem
  • the card games