A Converse Tale
February 4, 2011, 12:00 amFor the past 6 years I’ve been explaining converse (of the inverse, converse, and contrapositive fame) by saying that you can switch your Converse® shoes from left to right (although potentially uncomfortable), but you certainly cannot negate your Converse® shoes.
Today a volunteer stepped up...
Two Classic Puzzlers from Cartalk
January 21, 2011, 12:00 amPuzzler 1:
Every two-digit number can be represented as AB, where B is the ones digit and A is the tens digit. Right? So for example the number 43, A is 4 and B is 3.
Imagine then that you took this two-digit number and you squared it, AB x AB, and when you did that the result was a three-digi...
The App Store – 10 Billion
January 14, 2011, 12:00 am
Developing Math Intuition
January 14, 2011, 12:00 amGreat post: http://math-blog.com/2011/01/13/developing-math-intuition/
Our initial exposure to an idea shapes our intuition. And our intuition impacts how much we enjoy a subject. What do I mean?
Suppose we want to define a “cat”:
- Caveman definition: A furry animal with claws, teeth, a...
Today is brought to you by the number 73
January 13, 2011, 12:00 amHere’s a great set of facts about the number 73 (a Chuck Norris Number, sidenote I might grow to like that show but I can’t stand the laugh track):
- The mirror of 73, the 21st prime number, 37, is the 12th prime number. The number 21 has factors 7 and 3.
- In binary, 73 is a palindrome – 10...
Two Great Puzzlers from Cartalk
January 10, 2011, 12:00 am1. Cats, Dogs and Mice – Oh My!
RAY: You’re given a hundred dollars and told to spend it all purchasing exactly a hundred animals at the pet store. Dogs cost $15. Cats cost a buck, and mice are 25 cents each.
TOM: Let me get this straight. You have to spend exactly a hundred bucks and yo...
SBG: One Small Success
January 8, 2011, 12:00 amThis is a quick post describing one small reason (of many) of why I like SBG.
The setup for the gradebook is as follows: each student gets 2 shots (in class) to quiz on each topic, the grade is out of 4. They get one chance right after the end of the unit, and one a week later. If they improve fr...
Fun with Buckyball Magnets
January 6, 2011, 12:00 am
Alcumus
January 6, 2011, 12:00 amFrom Webmaths: Pretty cool website, a bit like Project Euler, but with more approachable difficulty level: http://www.artofproblemsolving.com/Alcumus/Introduction.php
Sample Problem:
The leveling up system they have could be an excellent way to get students addicted to solving some novel m...