# Math Puzzles, Please!

August 7, 2013 7:30 PM Subscribe

"Math for Smarty Pants" was awesome -- recommend me more books like that for a kid who loves math puzzles.

My 10 yr old missed the bus home from school earlier this year because he was so engrossed with a math puzzle he invented. The question was how to find the sum of a sequence of squares - e.g., 1+4+9+16, etc. In case you were wondering, it's called the Cannonball Problem and there is a solution, just not one that I understand. My kid doesn't either, but it's probably only a matter of time.

He loves paradoxes and silly humor, so the book Math for Smarty Pants - discovered via mefi - was a huge hit. Give me some more recommendations for fun books containing math puzzles!

My 10 yr old missed the bus home from school earlier this year because he was so engrossed with a math puzzle he invented. The question was how to find the sum of a sequence of squares - e.g., 1+4+9+16, etc. In case you were wondering, it's called the Cannonball Problem and there is a solution, just not one that I understand. My kid doesn't either, but it's probably only a matter of time.

He loves paradoxes and silly humor, so the book Math for Smarty Pants - discovered via mefi - was a huge hit. Give me some more recommendations for fun books containing math puzzles!

I enjoyed Sideways school at that age, especially because I liked other Louis Sachar books.

posted by tinymegalo at 9:38 PM on August 7, 2013

posted by tinymegalo at 9:38 PM on August 7, 2013

At that age, I was boggled for an entire year by Flatland: A Romance of Many Dimensions, by Edwin A. Abbott. It's available from Dover books in hardcopy too.

posted by bonehead at 10:14 PM on August 7, 2013

posted by bonehead at 10:14 PM on August 7, 2013

Link to The Number Devil.

Among the cool things I learned when my son read the Number Devil is the fact that perfect squares are the sums of successive odd numbers. What? Let's see:

Start with the perfect square 4 (which is 2^2) and the odd number 5. Then add successive odd numbers: 5, 7, 9, 11, etc to get the successive perfect squares.

4 + 5 = 9 (3^2)

9 + 7 = 16 (4^2)

16 + 9 = 25 (5^2)

25 + 11 = 36 (6^2)

36 + 13 = 49 (7^2)

Understanding why this makes sense will also teach you why they are called "square numbers".

posted by alms at 7:53 AM on August 8, 2013

Among the cool things I learned when my son read the Number Devil is the fact that perfect squares are the sums of successive odd numbers. What? Let's see:

Start with the perfect square 4 (which is 2^2) and the odd number 5. Then add successive odd numbers: 5, 7, 9, 11, etc to get the successive perfect squares.

4 + 5 = 9 (3^2)

9 + 7 = 16 (4^2)

16 + 9 = 25 (5^2)

25 + 11 = 36 (6^2)

36 + 13 = 49 (7^2)

Understanding why this makes sense will also teach you why they are called "square numbers".

posted by alms at 7:53 AM on August 8, 2013

Marilyn Burns also wrote The I Hate Mathematics Book, also a Brown School Paperback.

One of my favorite books as a kid.

posted by wittgenstein at 6:55 PM on August 8, 2013 [1 favorite]

One of my favorite books as a kid.

posted by wittgenstein at 6:55 PM on August 8, 2013 [1 favorite]

Thanks everyone! All of these have been ordered, downloaded or viewed. I'll ask my son which to mark best answer. And I'm looking forward to doing some of these puzzles myself too.

posted by selfmedicating at 3:10 PM on August 9, 2013

posted by selfmedicating at 3:10 PM on August 9, 2013

Follow-up: He liked all of these, but the favorite was The Number Devil so I marked it best answer. Also, I hadn't heard of the Sideways School ones before but those are great. They must be popular at his school since I recognized some of the problems in them.

Discussing this question with friends, I also got pointed to this cool tutorial on how to make a mobius bagel: Mathematically Correct Breakfast - How to Slice a Bagel into Two Linked Halves. It came from Maria Miller's math newsletter.

posted by selfmedicating at 1:56 PM on September 7, 2013

Discussing this question with friends, I also got pointed to this cool tutorial on how to make a mobius bagel: Mathematically Correct Breakfast - How to Slice a Bagel into Two Linked Halves. It came from Maria Miller's math newsletter.

posted by selfmedicating at 1:56 PM on September 7, 2013

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posted by telegraph at 7:51 PM on August 7, 2013