Photo by paparutzi.
Math concepts: addition, subtraction, negative numbers, mental math, absolute value
Number of players: any number
Equipment: math cards (two decks may be needed for a large group)
One player (the dealer) shuffles the math cards and deals one card face down for each player, beginning with the player on his left and proceeding in turn around the table. Then he deals one card face up beside each face down card.
Math concepts: odd numbers, even numbers, greater-than/less-than, rounding off, addition, subtraction, multiplication, division, fractions, negative numbers, prime numbers, square numbers, problem solving, mental math
Number of players: two or more
Equipment: pencil (or pen) and paper for every player
Math concepts: slope, logical strategy
Number of players: 2 or more
Equipment: 4×4 or larger grid, pebbles or other tokens to mark squares
Alexandria Jones and her brother Leon played Avoid Three with pebbles on a grid scratched in the sand, but you can also use pencils or markers on graph paper. You need a rectangular playing area at least 4×4 squares large. The bigger your grid, the longer your game.
Photo by peigianlong.
Here is a puzzle from Just a Substitute Teacher:
Lesson plan entry: “Hand out worksheet packets and have students staple before starting. They know what to do.”
Sounds simple enough! Four numbered sheets, eight total pages, printed front and back. What could go wrong?
Do you know how many possible combinations four pieces of paper can be arranged for stapling?
Continue reading Substitute Teacher Experiments with Combinatorics
[Feature photo above by pauladamsmith.]
Now there is an ancient Greek letter,
And I think no other is better.
It isn’t too tall,
It might look very small,
But its digits, they go on forever.— Scott
Mrs. Mitchell’s Virtual School
Are your students doing anything special for 
If you need ideas, here are some great
Photo by Sister72.
Dave at MathNotations offers another version of Nim that will give your students something to think about:
[1,2]-3-[4,5]-6-[7,8]…21 Helping Children Devise and Understand Winning Strategies
Math concepts: subtraction within 100, number patterns, mental math
Number of players: 2 or 3
Equipment: printed hundred chart (also called a hundred board), and highlighter or translucent disks to mark numbers — or use this online hundred chart
Place the hundred chart and highlighter where all players can reach them.
Are you ready for a challenge? Join us for the 2008 Mathematics Game. Here are the rules:
Use the digits in the year 2008 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, 8 may be used.
- Multi-digit numbers such as 20, 208, or .02 MAY be used this year.
- The square function may NOT be used.
- The integer function may NOT be used.
By definition:
[See Dr. Math’s Why does 0 factorial equal 1?]
For this game we will accept the value:
[See the Dr. Math FAQ 0 to the 0 power.]
As we all head back to school, here are some interesting calendar puzzles:
Most of our math contest preparation consists of working lots and lots of old test problems. Occasionally, however, I put together a tip sheet summarizing a topic that my students have trouble remembering.
Denise Gaskins' Let's Play Math 