Best of “Let’s Play Math!” in 2007

Farewell to 2007. We have snacks on the table so we can munch the night away, and the little ones are giggling over their Barbies, thrilled at the prospect of more sugar than is good for them.

The teenagers have launched their annual movie marathon. This year, it was the girls’ turn to invite friends over, so the men in my life have all found excuses to run into town.

Meanwhile, I am hiding in my den, indulging myself in a sort of blogger’s nostalgia. Some of the following posts got a lot of attention when they were published, others not so much. Topics range from preschool to high school, from kindergarten games to teaching fractions to Shakespearean insults, so I hope there is something to interest everyone.

[The photos are small so this article won’t take forever to load. Click on any picture to view a larger image.]

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 post. Figure them out for yourself — and then check the answers just to prove that you got them right.

Alexandria Jones and the Christmas Present Quandary

Magic Square Puzzles

Magic Square Puzzles

Alex handed her brother Leonhard a box wrapped in the rocket tessellation paper, with air holes carefully punched in two sides.

“Merry Christmas, Leon!” she said.

He ripped open the gift. Alex winced. Boys have no artistic appreciation, she thought.

“Oh, cool! Thanks,” Leon said.

“His name is Lo-shu,” said Alex. “But be careful. I used non-toxic tempera paint. The design will was off.”

Leon turned the turtle and studied the back of its shell. “Oh, that’s just like in the legend! I’ll copy it down before I let him near any water.”

• What do the shapes on Lo-shu’s back mean?
• Why are some dots white and some black?

Give Thanks to the Lord, for He Is Good

For to us a child is born,
to us a son is given,
and the government will be on his shoulders.
And he will be called
Wonderful Counselor,
Mighty God,
Everlasting Father,
Prince of Peace.

Of the increase of his government and peace
there will be no end.
He will reign on David’s throne and over his kingdom,
establishing and upholding it
with justice and righteousness
from that time on and forever.

The zeal of the Lord Almighty
will accomplish this.

— Isaiah 9:6-9

[Taken from the Holy Bible, New International Version, (c)1973, 1978, 1984 by the International Bible Society, used by permission of Zondervan Bible Publishers.]

Here is the simplest puzzle from the November/December 1998 issue of Alexandria Jones stories. The answer (and more puzzles) will follow.

Christmas gift for Leon (pdf, 68KB)

More puzzles are now here:

Magic square puzzles

To Be Continued…

Read all the posts from the November/December 1998 issue of my Mathematical Adventures of Alexandria Jones newsletter.

The Golden Christmas Tree

Last time, Alexandria Jones and her family were on their way to Uncle William’s tree farm to find the perfect Christmas tree, and Dr. Jones taught us about the Golden Section:

$The \; Golden \; Section \; ratio$

|———————A———————|————B————|

$A \; is \; to \; B \; as \; \left(A + B \right) \; is \; to \; A, \; or . . .$

$\frac{A}{B} = \frac{A + B}{A} = \: ?$

I gave you three algebra puzzles to solve. Did you try them?

• What is the exact value of the Golden Section ratio?

• If a 7-foot tree will fit in the Jones family’s living room, allowing for the tree stand and for a star on top, how wide will the tree be?
• Approximately how much surface area will Alex and Leon have to fill with lights and ornaments?

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 have not worked these problems yet, go back to the original post. Figure them out for yourself — and then check the answers just to prove that you got them right.

Math Bloggers Hall of Fame

What makes a great math blog? That depends on who is doing the judging, of course. Your list of Hall of Fame bloggers would surely be different than mine. But since this is my list, the qualifications were:

1. The nominee had to catch my interest. The content couldn’t be too abstract or specialized (since I have forgotten almost all the math I learned in college), but it had to be mathy enough to draw me in.
2. The blogger had to reward my reading time with good stories, thoughtful comments, imaginative puzzles, or really cool pictures — anything that kept me coming back and wishing for more.

So without further ado, the winners, listed alphabetically to avoid playing favorites among my favorites. Here are eleven of the best math-related blogs, the guys and gals who make me think:

Christmas Math Puzzles and Activities

UPDATE: Some of the links below have gone missing, as internet sites tend to do. Check out my *huge* new blog post:

We interrupt our regularly scheduled math program to bring you the following Christmas links…

First, A to Z Home’s Cool offers some fun for older students and teachers:

Also check out the annual Price of Christmas Index to see what the “12 Days of Christmas” gifts would cost you this year. Or explore the Nrich Advent Math Calendars to play with a new math activity every day until Christmas.

You can find just the song here: http://vihart.com/music/gauss12days.mp3.

Pre-Algebra Picture Puzzles

Maria at Homeschool Math Blog has posted a fun set of worksheets:
Pan balance problems to teach algebraic reasoning.

Princess Kitten, at nearly 9yo, keeps telling me, “I hate math, but I like algebra.” So I printed all four pages for her to try. These get pretty complicated, and the 2-variable problems had her flummoxed for awhile. But after an explanation and bit of pouting (I think she hates math because she’s such a perfectionist that she can’t bear to get something wrong, even the first time), she came back and conquered the toughest ones.