[Photo by reubenaingber.]
If you collected stacks of $100 bills, could you fit a trillion dollars into your bedroom?
In your house?
In a warehouse?
If you spent a dollar a second, how long would it take to spend a trillion dollars?
[HT: Justin Taylor at Between Two Worlds.]
[Photo by arsheffield.]
Check it out:
And coming soon: Pi Day.
Edited to add: Jonathan‘s class enjoyed extending the concept to include other products. Using the m/d/yy format (not the 4-digit year), how many times in your life has it been true that 
[Feature photo above by Tom@HK.]
One of my favorite warm-up exercises for Math Club is “Today is ______.” Each student invents one or more mathematical expressions for today’s date and writes his or her favorite on the board for all to admire. Answers range from lazy (24×1 — at least it’s an excuse to talk about identity elements) to unnecessarily repetitive (1+1+1+…), but we usually get a few gems as well.
[Photo by angela7dreams.]
A forum friend posted about her daughter’s adventure in learning the math facts:
“She loves stories and drawing, so I came up with the Math Friends book. She made a little book, and we talked about different numbers that are buddies.”
[Photo by Amanda M Hatfield.]
Have you made a resolution to exercise your mental muscles this year? Then please join us for the 2009 Mathematics Game. Here are the rules:
Use the digits in the year 2009 and the operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial) — along with parentheses, brackets, or other grouping symbols — to write expressions for the counting numbers 1 through 100.
- All four digits must be used in each expression.
- Only the digits 2, 0, 0, 9 may be used.
- The decimal point may be used, as in .9, .02, etc.
- Multi-digit numbers such as 29 or 902 may be used, but preference is given to solutions that avoid them.
By definition: 
[See Dr. Math’s Why does 0 factorial equal 1?]
For this game we will accept: 
[See the Dr. Math FAQ 0 to the 0 power.]
[Photo by theogeo.]
Christmas afternoon is a slow time at our house. How shall we while away the hours until the turkey is done? With math, of course!
Check out this puzzle from Blinkdagger.
[Feature photo above “You’re a mean one, Mr. Grinch” from CheezBurger.com.]
Okay, kids, I know you’re on break, but Mr. Grinch would tell you that’s no excuse to laze around playing games and eating cookies. There is only a month until our school MathCounts competition, which doesn’t give you much time to prepare. I’ve collected several resources to build up your mental muscle-power before the test…
[Photo by Photo Mojo via Flickr (CC BY 2.0).]
Yahtzee and other board games provide a modicum of math fact practice. But for intensive, thought-provoking math drill, I can’t think of any game that would beat Contig.
Math concepts: addition, subtraction, multiplication, division, order of operations, mental math
Number of players: 2 – 4
Equipment: Contig game board, three 6-sided dice, pencil and scratch paper for keeping score, and bingo chips or wide-tip markers to mark game squares
Place the game board and dice between players, and give each player a marker or pile of chips. (Markers do not need to be different colors.) Write the players’ names at the top of the scratch paper to make a score sheet.
[Photo by One Laptop Per Child.]
Once again, I am adding to my Free (Mostly) Math Resources page. Here are a handful of helpful websites for teaching math…
[Photo by fdecomite.]
I stumbled across this cool project during a Creative Commons search at Flickr. Can you guess what it is?
