Puzzles – Page 9 – Denise Gaskins' Let's Play Math

2011 Mathematics Game

Posted on January 1, 2011May 13, 2022 by Denise Gaskins

[Photo from Wikipedia.]

Two of the most popular New Year’s Resolutions are to spend more time with family and friends, and to get more exercise. The 2011 Mathematics Game is a chance to do both at once.

So grab a partner, slip into your workout clothes, and pump up those mental muscles!

Here are the rules:

Use the digits in the year 2011 to write mathematical expressions for the counting numbers 1 through 100.

All four digits must be used in each expression. You may not use any other numbers except 2, 0, 1, and 1.

You may use the arithmetic operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial). You may also use parentheses, brackets, or other grouping symbols.

You may use a decimal point to create numbers such as .1, .02, etc.

Multi-digit numbers such as 20 or 102 may be used, but preference is given to solutions that avoid them.

Bonus Rules
You may use the overhead-bar (vinculum), dots, or brackets to mark a repeating decimal.

You may use multifactorials:

(n!)! = a factorial of a factorial, which is not the same as a multifactorial

n!! = a double factorial = the product of all integers from 1 to n that have the same parity (odd or even) as n

n!!! = a triple factorial = the product of all integers from 1 to n that are equal to n mod 3

[Note to teachers: The bonus rules are not part of the Math Forum guidelines. They make a significant difference in the number of possible solutions, however, and they should not be too difficult for high school students or advanced middle schoolers.]

Continue reading 2011 Mathematics Game

A Football Puzzle

Posted on November 29, 2010May 13, 2022 by Denise Gaskins

[Photo by rdesai.]

The MIT Mathmen got the ball on their own 20-yard line for the last drive of the game. They were down by 2 points, so they needed at least a field goal to win the game.

If quarterback Zeno and his offense advanced the ball halfway to the opposing team’s end zone on each play…

Continue reading A Football Puzzle

Logic Games at Blogging 2 Learn

Posted on November 23, 2010May 13, 2022 by Denise Gaskins

http://www.wpclipart.com/money/. Per the licen... — Image via Wikipedia

For the rest of NaBloPoMo (National Blog Posting Month), my other blog is featuring a logic game or puzzle every day. So far, I’ve shared three of my online favorites:

And there’s plenty more fun to come. Drop in every day until December to see a new puzzle or game:

Blogging 2 Learn

A Couple of Chess Puzzles

Posted on October 25, 2010May 13, 2022 by Denise Gaskins

Chess is a favorite game for recreational mathematicians — not to play it, but to play around with it. Many puzzles and challenges are based on the moves of chess pieces.

Stretch your brain with these puzzles:

Can you go on a Knight’s Tour? Start your knight on any square, and try to hop around to all the rest.

Or, how many queens can you place on the board so that no queen can capture another?

Continue reading A Couple of Chess Puzzles

2010 Mathematics Game Update

Posted on October 20, 2010May 13, 2022 by Denise Gaskins

[Photo by pfala.]

Thanks to John Cook’s article about factorials in the recent Mathematics and Multimedia Carnival, we’re adding new rules to the 2010 Mathematics Game.

Let’s play with multifactorials!

Continue reading 2010 Mathematics Game Update

Lewis Carroll’s Logic Challenges

Posted on October 11, 2010May 13, 2022 by Denise Gaskins

Symbolic Logic Part I was published in 1896. When Lewis Carroll (Charles Lutwidge Dodgson) died two years later, Part II was lost. Because they couldn’t find the manuscript, many people doubted that he ever wrote Part II. But almost eighty years after his death, portions of Part II were recovered and finally published. The following puzzles are from the combined volume, Lewis Carroll’s Symbolic Logic, edited by William Warren Bartley, III.

These puzzles are called soriteses or polysyllogisms. Carroll began with a series of “if this, then that” statements. He rewrote them to make them more confusing, and then he mixed up the order to create a challenging puzzle.

Given each set of premises, what conclusion can you reach?

Continue reading Lewis Carroll’s Logic Challenges

How to Start an Argument: The Monty Hall Problem

Posted on August 16, 2010May 13, 2022 by Denise Gaskins

[Photo by MontyPython.]

You can get a good argument going in almost any group of people with the infamous Monty Hall problem:

Imagine you are on a TV game show, and the host lets you choose between three closed doors. One of the doors hides a fancy sports car, and if you pick that door, you win the car.

You pick door #1.

The host opens door #3 to reveal a goat. Then he gives you a chance to switch your door for the unopened door #2.

Should you switch?

What if you say you’re going to switch, and then the host offers to give you $5,000 instead of whatever is behind door #2?

Try the game for yourself at the Stay or Switch website.

Continue reading How to Start an Argument: The Monty Hall Problem

Brighten Up Your Monday with Puzzles

Posted on August 2, 2010May 13, 2022 by Denise Gaskins

Mondays come every week. Bleh! Here are some puzzles I found this weekend, to brighten up your day…

[Update + Forgetful Waiter Puzzle from singingbanana.]

Continue reading Brighten Up Your Monday with Puzzles

2010 Mathematics Game

Posted on January 1, 2010May 13, 2022 by Denise Gaskins

[Photo by pfala.]

Did you know that playing games is one of the Top 10 Ways To Improve Your Brain Fitness? So slip into your workout clothes and pump up those mental muscles with the 2010 Mathematics Game!

Here are the rules:

Use the digits in the year 2010 to write mathematical expressions for the counting numbers 1 through 100.

All four digits must be used in each expression. You may not use any other numbers except 2, 0, 1, and 0.

You may use the arithmetic operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial). You may also use parentheses, brackets, or other grouping symbols.

You may use a decimal point to create numbers such as .1, .02, etc.

Multi-digit numbers such as 20 or 102 may be used, but preference is given to solutions that avoid them.

Bonus Rule
You may use the overhead-bar (vinculum), dots, or brackets to mark a repeating decimal.

[Note to teachers: This rule is not part of the Math Forum guidelines. It makes a significant difference in the number of possible solutions, however, and it should not be too difficult for high school students or advanced middle schoolers.]

Continue reading 2010 Mathematics Game