Best of “Let’s Play Math!” in 2007

Cooking class

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.

Beach party

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.

Winter in Illinois

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, Captain Kitten 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.]

Continue reading Best of “Let’s Play Math!” in 2007

Christmas Puzzle Answers

Alexandria JonesRemember 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

Continue reading Christmas Puzzle Answers

Magic Square Puzzles

Lo-shu turtle

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?

Continue reading Magic Square Puzzles

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.]



Leon’s Christmas Gift

Lo-shu turtle

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)

Edited to Add

More puzzles are now here:

Magic square puzzles

Answers are also posted:

Christmas puzzle answers

To Be Continued…

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


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The Golden Christmas Tree

Christmas tree farm

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?

Christmas tree decorated

  • 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.

Continue reading The Golden Christmas Tree