Maria Jones hung up the phone and collapsed at the kitchen table. She buried her head in her hands and groaned. Alex looked up from her game of Solitaire.

“Let me guess,” she said. “Can’t-Say-No Syndrome, again?”

Mrs. Jones nodded. “This time I volunteered to plan an activity for next month’s homeschool group meeting.”

Leon wandered in and pulled an apple from the fruit bowl. “Ha!” he said. “She means she volunteered us to plan an activity, right?”

Mrs. Jones smiled. “That’s my motto: When in doubt, delegate!”

## A Homeschool Math Carnival

Alex picked up her cards and began shuffling. She stared at the cards, shuffling and shuffling until Leon asked, “Aren’t those cards mixed yet?”

Alex jumped. “Ack! You startled me. I was just thinking —”

“Ooh, that’s trouble!” Leon grinned.

“— Why don’t we plan a Math Fair?”

“Do you mean something like the Science Fair?” Mrs. Jones asked. “With judges and ribbons? That’s a bit much to organize by next month.”

Alex shook her head. “No, no. More like the county fair. Games and booths, you know — fun, hands-on stuff.”

“A mathematical carnival,” Leon said. “I like it!”

When the homeschool group’s newsletter came out, several families called to request a table. Alex kept a list of the plans. “Nim, tangrams, guess-the-number games, logic riddles… This is going to be great!” she said.

“And the thing I like best,” Mrs. Jones said, “is that all I have to do is to show up.”

## Leon Plays Math War

Leon waved an imaginary blaster at her. “Well, I’m gearing up for battle, so you’d better watch out!”

“What do you mean?” Alex asked.

“Math War. I’ll show you,” Leon said. He pulled a deck of cards out of his pocket.

“Hey, that’s my deck!” Alex snatched at the cards, but Leon pulled them away.

“You left them laying on the table. If you want them, you’ll have to win them back.” He split the deck and handed her half the cards. “By the way, we had a peasant uprising.”

“You mean you took out all the face cards,” Alex said.

Leon nodded. “That makes it a deck of Math Cards. No royalty — just numbers.”

“So how do I play?”

“You turn up two cards at once.” Leon demonstrated. “Then you multiply the numbers on your cards, and I multiply mine, and the highest product takes the trick.”

Alex took the first couple of tricks, but then her brother had a run of high cards.

“Are you sure you didn’t stack the deck, Leon?”

“Don’t you trust me?”

“I refuse to answer that.”

## A Twist in the Rules

She turned up her next pair of cards. Leon slammed his hand down and yelled, “Spy!”

Alex jumped. “What? Wait, give back my cards!”

Leon held up Alex’s joker. “You laid down a spy. Whoever captures him first takes the trick.”

“Now I know I don’t trust you.”

“You know what they say. All’s fair in War. You wanna concede?”

Alex shook her head. “But you need to explain the rules better at the Carnival. And you know, there will be some younger kids there. Do you think multiplication will be too hard?”

“Naw. I can do Addition War. And for older students, we can let the red cards be negative numbers. I’ll just let people pick the rules they want to play by.”

## Alex Tries Fraction War

“Okay,” Alex said, “I want to play with division.”

“How? The numbers mostly won’t come out even.”

“A fraction is a division problem, so whoever makes the biggest fraction wins. I turned up a 5 and a 7, and 5/7 beats your 2/3.”

“Hold it!” Leon frowned at the cards. “You forgot improper fractions. That’s not 2/3 — it’s 3/2, which beats 5/7 or 7/5. Either way, I win!”

## How to Plan Your Own Math Carnival

Although Alex and Leon are fictional characters, their adventure this month is based on a real Math Carnival. I put an ad (much like Alex’s blurb above) into our homeschool group newsletter. Two months later, we had a fun afternoon of math games, puzzles, and “mathemagic” tricks. Each of my Math Club students picked a favorite activity to demonstrate, and volunteer families filled the rest of the space. All I did was set up tables, open the door, and enjoy the fun!

Try it yourself, and let me know how it goes for you.

## To Be Continued…

Read all the posts from the September/October 1999 issue of my ** Mathematical Adventures of Alexandria Jones** newsletter.

This sounds like such a fun idea! I bet our local group would love to do something like this. I’m going to save this post as a reminder, and I’ll definitely let you know how it goes. Thanks!

I love the “Math War” idea. And there’s a nice extension. To make the game more strategic and provoke higher order thinking for students who know their basic facts cold, you can change the rules so that students can turn up 3 cards at a time, and then they have some interesting choices to make. Suppose they turn up 3,4, and 5–should they arrange them as 5×43 or 4×53 or 3×54 or4x35 or 5×34 or 3×45 if they want to have the best shot at beating their opponent? After a little practice and thought, they’ll quickly see that the last three of those choices are dominated by the first three, but it will take some actual figuring to figure out which of the first three to use. (There is actually a deep mathematical principle behind how you choose among the first three–and practice with this kind of game may help students develop the math intuition behind that idea as well as strengthening their computational fluency.) And, of course, no reason to stop with drawing 3 cards at a time once they understand the principle.

That’s a great extension. I think I will add it to the original Math War post, as well. Thank you!

The “math war” seems like a great opportunity for students to learn about and compare fractions!