- Announcements:
- Roll
- For next time: Read Ideas #9 (prime numbers), and #11 (Fibonacci
numbers); complete the homework assigned last time (see your assignment
page!).
- About the current assignment I'm returning
- You can't ignore a problem! Say something, even if
you merely show how you struggled to solve it. ("Just do it!")
- Think outside the box ("Examine issues from several points of view.")
- E.g. change the operation! 4+5=12 (base 7), 4+6=13 (base 7)
- Change the conditions! 4*5=14 (base 16), and
4*8=20 (base 16) -- we get to 20!
- Good beyond the box thinking....
- You can't have 2, 7, and 9 as digits base 2. There's
always a risk of confusion when we're moving around between
different bases, but keep your eyes on the ball. I can convert
1729 (base 10) to base 2, however....
- Could everyone who had some interesting links please send
them to me? That way I can compile them (and don't have to type
them in, perhaps incorrectly!). Thanks!
- Back to the bases!
- Back to the Ancient Egyptians and their division
- Let's try a few more. Here's a relatively easy one: Suppose Fatima had 3
loaves to share between 4 people. How would she do it?
- The value of the secret unit
fraction table in the Rhind
Papyrus (which dates to around 1650 BCE)
- A little trickier: How would you divide 5 by 9?
- How would you like to do story problems like this
one?!
- Why did
Egyptians do things this way? (an example division problem, using binary)
- "Decimals" in binary ("Binimals"?)
- Easy one: 3/8
- Harder one: 1/3
- One of my favorite early introductions to bases was Tom Lehrer's New
Math.
- Would you like to do more practice translating between bases?
- Today we play Detective in the times of Babylon....
- Links:
- To spoil the secret of the detectives, or for more details, see this link.
Website maintained by Andy Long.
Comments appreciated.