Like Brainteasers?

So do middle school kids.

Sometimes, when we finish a couple of minutes early, I like to do a couple with the class.

I've been using the same ones for several years, and it's interesting to see how quickly (if at all) the kids can figure them out. A few of my favorites follow. Now, I know that the Google search bar is just a few inches up, but no cheating!

(Don't worry - answers included below)! 

Feel free to post your favorites!

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Truth-Tellers and Lie-Tellers
You're walking through the woods, and you come to a fork in the path. You know that one direction leads to the Truth-Teller Village (where everyone always tells the truth), and the other leads to the Lie-Teller Village (where everyone always lies). At the fork in the road is an old man. You don't know whether he is a Truth-Teller or a Lie-Teller, but you are allowed to ask him one question. Your goal is to reach the Truth-Teller Village.
What question do you ask? 

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The Pattern

Take a look at the pattern to the left.
What comes next?

I love the "Ooooohhhhhhhhh," I get from kids on this one.





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 Pennies
 
Given the arrangement of pennies to the right,
move exactly one penny and create one row
and one column each containing exactly four pennies.



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And, the mother of them all...

1 11 21 1211

Given the following pattern, what is the next line?

1

11

21

1211

After a couple of minutes, I usually tell the kids that...
1. The math involved isn't anything a kindergartner couldn't do.
2. I never figured it out. Someone had to tell me (although I tried it for two weeks).
3. Just for fun, I usually tell them the next line - 111221 - and ask for the one after that.
    (It goes on forever) 

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Brainteaser Answers

Truth-Tellers and Lie-Tellers

You ask, "Which way to your village?"

A Truth-Teller tells the truth and points toward the Truth-Teller village.

A Lie-Teller tells a lie and points toward the Truth-Teller village.   

 

The Pattern

Given the image
to the left, I think
we can declare
this one solved!

Pennies

 

Place the uppermost
penny directly on top
of the center penny.

Four across, four down!   

1 11 21 1211

This is a "say what you see pattern.

Each line, when read out loud, describes the line immediately above it:

                             1 

                            11             "One 1"

                            21             "Two 1's"

                        1211          "One 2, One 1"

                      111221       "One 1, One 2, Two 1's" 

So, the next line would be...312211

That's, "Three 1's, Two 2's, One 1"