March Update: Expanding Blogroll

funny pictures

At our house, we’re fighting persistent colds, and I think these “new and improved” Puffs would be just the thing to cheer up my 9yo! Now that the season has officially turned, I need to put my talented photographer daughter to work on spring pictures for my header. Meanwhile, here is a round-up of the happenings at Let’s play math! blog this month…

Continue reading March Update: Expanding Blogroll

Retro-Dated Magic Square Puzzles

Lo-shu turtle

The hectic holidays kept me from finishing the Christmas stories of Alexandria Jones. I am finally getting them typed up, but I past-dated them to keep the seasonal connection. So if you want to read more, here are the newest posts:

Magic square puzzles

Christmas puzzle answers


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In Between Sneezes… Multiplication Videos

Sitting at home with a cold, tired of watching TV and playing video games, stumbled upon…

A great theorem from math history

The Infinitude of Primes

Continue reading In Between Sneezes… Multiplication Videos

Subtracting Mixed Numbers: A Cry for Help

Photo by powerbooktrance.

Paraphrased from a homeschool math discussion forum:

“Help me teach fractions! My son can do long subtraction problems that involve borrowing, and he can handle basic fraction math, but problems like 9  -  5 \frac{2}{5} give him a brain freeze. To me, this is an easy problem, but he can’t grasp the concept of borrowing from the whole number. It is even worse when the math book moves on to 10 \frac{1}{4}  -  2 \frac{3}{7} .”

Several homeschooling parents replied to this question, offering advice about various fraction manipulatives that might be used to demonstrate the concept. I am not sure that manipulatives are needed or helpful in this case. The boy seems to have the basic concept of subtraction down, but he gets flustered and is unsure of what to do in the more complicated mixed-number problems.

The mother says, “To me, this is an easy problem” — and that itself is one source of trouble. Too often, we adults (homeschoolers and classroom teachers alike) don’t appreciate how very complicated an operation we are asking our students to perform. A mixed-number calculation like this is an intricate dance that can seem overwhelming to a beginner.

I will go through the calculation one bite at a time, so you can see just how much a student must remember. As you read through the steps, pay attention to your own emotional reaction. Are you starting to feel a bit of brain freeze, too?

Afterward, we’ll discuss how to make the problem simpler…

Continue reading Subtracting Mixed Numbers: A Cry for Help

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 Answers to Alex’s and Leon’s Puzzles

Easter: He Is Risen!

sunrise off the bow
Photo by joiseyshowaa.

Praise be to the God and Father of our Lord Jesus Christ!
In his great mercy he has given us new birth into a living hope
through the resurrection of Jesus Christ from the dead,
and into an inheritance that can never perish, spoil or fade
— kept in heaven for you,
who through faith are shielded by God’s power
until the coming of the salvation
that is ready to be revealed in the last time.

In this you greatly rejoice,
though now for a little while
you may have had to suffer grief
in all kinds of trials.

Continue reading Easter: He Is Risen!