Pre-algebra – Denise Gaskins' Let's Play Math

Math Game Monday: Prism Power

Posted on March 16, 2026February 23, 2026 by Denise Gaskins

$Learn a new math game every week, for free$

This game encourages players to reason about the relationships between length dimensions and volume in a 3-D shape.

Many parents remember struggling to learn math. We hope to provide a better experience for our children. And one of the best ways for children to enjoy learning is through hands-on play.

So what are you waiting for? Let’s play some math!

Prism Power

Math Concepts: rectangular volume, cubic units.

Players: two or more.

Equipment: printed gameboard or plain paper, pencils or markers, one six-sided die, 40–50 cubic blocks per player.

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Math Game Monday: Factors and Multiples

Posted on March 2, 2026January 25, 2026 by Denise Gaskins

$Learn a new math game every week, for free$

This game blends strategy and factoring practice, challenging players to think several steps ahead.

Many parents remember struggling to learn math. We hope to provide a better experience for our children. And one of the best ways for children to enjoy learning is through hands-on play.

So what are you waiting for? Let’s play some math!

Factors and Multiples

Math Concepts: multiplication, division, factors and multiples.

Players: two to four.

Equipment: printed hundred chart, pencils or markers. Calculator optional.

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Math Game Monday: What’s My Rule?

Posted on February 9, 2026January 25, 2026 by Denise Gaskins

$Learn a new game with Math Game Monday$

This game challenges upper-elementary and middle school students to reason about number properties.

Many parents remember struggling to learn math. We hope to provide a better experience for our children.

And one of the best ways for children to enjoy learning is through hands-on play.

What’s My Rule?

Math Concepts: Venn diagrams, factors and multiples, divisibility, prime numbers, and other number properties.

Players: two or more.

Equipment: pencil and paper, or whiteboard and markers. Calculator optional.

Continue reading Math Game Monday: What’s My Rule?

Homeschool Memories: Bill Gates Proportions II

Posted on January 21, 2026January 3, 2026 by Denise Gaskins

Once upon a time, when my kids and I were young…

Later the same year, not too long after our discussion of the Bill Gates proportions, I stumbled on some more data. I discovered that the median American family’s net worth was $93,100 in 2004, most of that being home equity.

This gave me another chance to play around with proportions. And since I was preparing a workshop for our regional homeschooling conference, I wrote a sample problem:

The median American family has a net worth of about $100 thousand. Bill Gates has a net worth of $56 billion. If Average Jane Homeschooler spends $100 in the vendor hall, what would be the equivalent expense for Gates?

In the last post, I explained that a proportion sets two ratios equal to each other, like equivalent fractions. Each ratio must compare similar thing to similar thing in the same order.

In this case, we are interested in the ratio “Expense compared to Net Worth.”

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Homeschool Memories: Putting Bill Gates in Proportion

Posted on January 14, 2026January 3, 2026 by Denise Gaskins

Money Bag, dollar banknotes and stacked coins on wooden table

Once upon a time…

We were getting ready for the annual homeschool co-op speech contest, and a friend emailed me for help.

“Can you help us figure out how to figure out this problem?

“This is related to C’s speech. I think we have all the information we need, but I’m not sure:

“The average household income in the United States is $60,000/year. And a man’s annual income is $56 billion.

“Is there a way to figure out what this man’s value of a million dollars would be, compared to the person who earns $60,000/year? In other words, I would like to say—$1,000,000 to us is like 10 cents to Bill Gates.”

We found out later that her son’s numbers weren’t exactly right. He hadn’t understood the difference between income and net worth, so he made Gates sound richer than reality.

But the basic math principles never change, and it’s fun to play with big numbers.

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Musings: Math is Communication

Posted on December 10, 2025November 11, 2025 by Denise Gaskins

$Young boy writing math expressions$

The question came up on a homeschool math forum:

“My first grader and I were playing with equivalent expressions. We were trying to see how many ways we could write the value ‘3.’

“He wrote down 10 – 2 × 3 + 1.

“When I tried to explain the problem with his calculation, he got frustrated and didn’t want to do math.

“How can I help him understand order of operations?”

[If you think this sounds like too complex of a math expression for a first grader, you may want to read my blog post about math manipulatives and big ideas.]

Order of operations doesn’t matter in this instance. What matters is communication.

The mother didn’t know how to read what her son wrote.

He could help her understand by putting parentheses around the part he wanted her to read first.

He doesn’t need to know abstract rules for arbitrary calculations, or all the different ways we might possibly misunderstand each other. He just needs to know how to say what is in his mind.

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Happy Pythagorean Triple Day!

Posted on July 22, 2025July 28, 2025 by Denise Gaskins

Pythagorean Theorem demonstrated with tangrams

Thursday is Pythagorean Triple Day, one of the rarest math holidays.

The numbers of Thursday’s date: 7/24/25 or 24/7/25, fit the pattern of the Pythagorean Theorem: 7 squared + 24 squared = 25 squared.

Any three numbers that fit the a² + b² = c² pattern form a Pythagorean Triple.

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Math Journal: Playing with My Own Ignorance

Posted on March 12, 2025February 24, 2025 by Denise Gaskins

Mary Everest Boole, wife of English mathematician George Boole, once described algebra as “thinking logically about the fact of our own ignorance.”

This definition made me chuckle. Like any human being, I am ignorant on many things, but I usually avoid thinking about that.

So I wondered what would happen if I took Mrs. Boole’s advice and tried thinking logically about my ignorance.

How far could I go?

Perhaps you’d like to try this experiment with your children. All you need is a pen and paper or a whiteboard and markers and a bit of curiosity.

And if you enjoy this exploration, check out my Math Journaling Adventures project to discover how playful writing activities can help your students learn mathematics. Preorder your books today!

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The Best Math Game Ever

Posted on August 25, 2020December 30, 2024 by Denise Gaskins

The Substitution Game features low-floor, high-ceiling cooperative play that works with any age (or with a mixed-age group) — and you can use it while distance learning, too. It’s great for building algebraic thinking.

Excerpted from my new book, Prealgebra & Geometry: Math Games for Middle School. Look for it at your favorite online bookstore.

The Substitution Game

Math Concepts: addition, subtraction, multiplication, division, order of operations, integers, fractions, equivalence and substitution.

Players: any number (a cooperative game).

Equipment: whiteboard and markers (preferred) or pencil and paper to share. Calculator optional.

Math Game: Hit Me

Posted on August 11, 2020February 8, 2024 by Denise Gaskins

I believe this was the first math game I ever invented. Of course, ideas are common currency, so I’m sure other math teachers thought of it before I did. But to me, it was original.

I’ve blogged about the game before, but here’s the updated version as it appears in my new book Prealgebra & Geometry: Math Games for Middle School — scheduled for publication in early 2021. Sign up for my newsletter to get updates.

Hit Me

Math Concepts: integer addition, absolute value.

Players: two or more.

Equipment: playing cards (two decks may be needed for a large group).

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