Logic: The Centauri Challenge

Another fun discovery from the #MTBoS Challenge: Brian Miller (@TheMillerMath) posted this interstellar puzzle on his blog today.

[Right-click image to download a pdf you can print for your students.]

More Logic Puzzles

If you liked the Centauri Challenge, you may also enjoy the following blog posts:

Get all our new math tips and games:  Subscribe in a reader, or get updates by Email.

Sample The Moscow Puzzles

Dover Publications is offering a free sample chapter from The Moscow Puzzles.

Cat and Mice
Purrer has decided to take a nap. He dreams he is encircle by 13 mice: 12 gray and 1 white. He hears his owner saying: “Purrer, you are to eat each thirteenth mouse, keeping the same direction. The last mouse you eat must be the white one.”

Download the sample chapter from The Moscow Puzzles.

More Free Math from Dover Publications

Tabletop Academy PressGet monthly math tips and activity ideas, and be the first to hear about new books, revisions, and sales or other promotions. Sign up for my Tabletop Academy Press Updates email list.

Olympic Logic

I love logic puzzles! Nrich Maths offers four fun Olympics Logic puzzles. And be sure to check out the rest of their Nrich Olympics Math as well.

Medals Count

Given the following clues, can you work out the number of gold, silver and bronze medals that France, Italy and Japan got in this international sports competition?

  • Japan has 1 more gold medal, but 3 fewer silver medals, than Italy.
  • France has the most bronze medals (18), but fewest gold medals (7).
  • Each country has at least 6 medals of each type.
  • Italy has 27 medals in total.
  • Italy has 2 more bronze medals than gold medals.
  • The three countries have 38 bronze medals in total.
  • France has twice as many silver medals as Italy has gold medals.

Go to Nrich Maths and try all four puzzles!

Get all our new math tips and games:  Subscribe in a reader, or get updates by Email.

Skit: Knights and Knaves Logic Puzzles

photo by puuikibeach via flickr

Our homeschool co-op held an end-of-semester assembly. Each class was supposed to demonstrate something they had learned. I planned to set up a static display showing some of our projects, like the fractal pop-up card and the game of Nim, but the students voted to do a skit based on the logic puzzles of Raymond Smullyan.

We had a small class (only four students), but you can easily divide up the lines make room for more players. We created signs from half-sheets of poster board with each native’s line on front and whether she was a knight or knave on the flip side. In the course of a skit, there isn’t enough time to really think through the puzzles, so the audience had to vote based on first impressions — which gave us a fair showing of all opinions on each puzzle.

Continue reading

Raymond Smullyan Excerpts at Dover Publications

To celebrate their re-release of his classic puzzle books, the Dover Math and Science Newsletter featured an interview with Raymond Smullyan, as well as several extended excerpts from his books. (For my math club students: Professor Smullyan invented the Knights and Knaves puzzles.) Enjoy!

Get all our new math tips and games:  Subscribe in a reader, or get updates by Email.

Free Math from Dover Publications

I love Dover books, don’t you? They publish so-o-o-o-o many interesting titles at reasonable prices. I always have several Dover books on my wishlist, waiting for my next free gift card from Swagbucks.

But you don’t have to wait to enjoy free math from Dover books. Sign up for the Dover Sampler, and each week they will send an email with links to content from all sorts of books. Or try the Dover Children’s Sampler and Dover Teacher’s Sampler for coloring books, mazes, literature, and more. All the Dover samplers are completely free, and you can cancel at any time.

From Last Week’s Sampler

Last week’s email included a section on “Exploring Mathematics”:

And that’s only the beginning. Below, I’ve listed a wide variety of math-related links collected from past samplers (though be warned: Dover does change its page links from time to time). Download, print, enjoy!

Continue reading

Logic Games at Blogging 2 Learn

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:

Don’t miss any of “Let’s Play Math!”:  Subscribe in a reader, or get updates by Email.

Lewis Carroll’s Logic Challenges

Workplace stress caused by an unsuitable work ...

Image via Wikipedia

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


30+ Things to Do with a Hundred Chart

[Photo by geishaboy500.]

Are you looking for creative ways to help your children study math? Even without a workbook or teacher’s manual, your kids can learn a lot about numbers. Just spend an afternoon playing around with a hundred chart (also called a hundred board or hundred grid).

Here are a few ideas to get you started…

Continue reading

Quotes XXI: How Is Logic Like Whiskey?

Photo by Brian – Progressive Spin.

Logic is the science of making valid deductions and proofs — and it is also a fruitful topic for blackboard quotes. Here are a few of my favorites:

You can only find truth with logic if you have already found truth without it.

G. K. Chesterton
The Man Who Was Orthodox

Continue reading

Answers to Alex’s and Leon’s Puzzles

Remember the Math Adventurer’s Rule: Figure it out for yourself! Whenever I give a problem in an Alexandria Jones story, I will try to post the answer soon afterward. But don’t peek! If I tell you the answer, you miss out on the fun of solving the puzzle. So if you haven’t worked these problems yet, go back to the original posts. Figure them out for yourself — and then check the answers just to prove that you got them right.

Leonhard’s block puzzles

Alex’s & Leon’s homeschool puzzle

Continue reading

giggle snort

Alex’s & Leon’s Homeschool Puzzle

Photo by gotplaid?.

While checking out the book table after a homeschool group meeting, Maria Jones glanced up to see her children laughing with some kids she did not recognize. Driving home, she asked about the new family, but Alex and Leon had been too busy exchanging silly stories to even ask the strangers’ names.

“Well,” Leon said, “the boy told me he has twice as many sisters as brothers.”

No way!” said Alex. “The girl told me that she has the same number of brothers and sisters.”

How can that be?

Continue reading

Leonhard’s Block Puzzles

Leon’s wooden block puzzle Leonhard Jones is Alexandria Jones’s younger brother. He enjoys woodworking, and he cut a wooden cube into 8 smaller blocks to make himself a puzzle.

Puzzle #1

Leon painted the 8 blocks with his two favorite colors: red and forest green. When he was finished, Leon could put the blocks together into a red cube, or he could switch them around to make a green cube.

How did Leon paint his blocks?

Continue reading

Math Club Nim

Photo by Windell Oskay via flickr.

Math concepts: logic, patterns, divisibility
Number of players: 2
Equipment: 10 tokens, any sort, mix or match

Set Up

Place the pile of tokens (pebbles, toothpicks, beans, pennies, dry cereal, etc.) on the table between the players.

Continue reading

Test Yourself: Logic

Can you solve the Wason Selection Task puzzle at Text Savvy blog? [Blog has disappeared.]

Here is an interactive version of the Wason Selection Task, and you can find out more information about it on the Wikipedia page.

Warning: Don’t read the comments Wikipedia page until you have tried the puzzle for yourself. Why ruin your fun?

Don’t miss any of “Let’s Play Math!”:  Subscribe in a reader, or get updates by Email.

Have more fun on Let’s Play Math! blog:

Puzzle: Logic Test

If you enjoy Raymond Smullyan’s The Lady or the Tiger and similar puzzles, you will probably have fun with this Logic test, posted by JD2718. JD has a wide variety of other math puzzles at his site, so take the time to browse a bit.

Don’t miss any of “Let’s Play Math!”:  Subscribe in a reader, or get updates by Email.

Have more fun on Let’s Play Math! blog:

Confession: I Am Not Good at Math

I want to tell you a story. Everyone likes a story, right? But at the heart of my story lies a confession that I am afraid will shock many readers. People assume that because I teach math, blog about math, give advice about math on internet forums, and present workshops about teaching math — because I do all this, I must be good at math.

Apply logic to that statement. The conclusion simply isn’t valid.

Continue reading

Math Humor, and Some Copywork Resources

[Rescued from my old blog.]

I have been reading up on Charlotte Mason’s teaching style, and I plan to incorporate more copywork and dictation into our school program next year. Here are a few of my favorite funny quotes about math. (These would also make great blackboard quotes for a math classroom.)

Continue reading