Playful Math Snacks for August: Logic Puzzles

Posted on by Denise Gaskins

The August “Let’s Play Math” newsletter went out last week to everyone who signed up for Tabletop Academy Press math updates. This month’s issue focuses on logic puzzles for all ages, including a newly-discovered deleted scene from Harry Potter and the Sorcerer’s Stone. What fun!

If you missed this month’s edition, no worries—‌here are some great puzzles from the Let’s Play Math blog archive:

The Centauri Logic Challenge

Sign Up Today

If you missed this month’s edition, no worries — there will be more playful math snacks coming soon. Click the link below to sign up today!

And remember: Newsletter subscribers are always the first to hear about new books, revisions, and sales or other promotions.

New Hundred Chart Game: Odd-Even-Prime Race

Posted on by Denise Gaskins

100chart[Photo by geishaboy500 (CC BY 2.0).]

Counting all the fractional variations, my massive blog post 30+ Things to Do with a Hundred Chart now offers nearly forty ideas for playing around with numbers from preschool to prealgebra.

Here is the newest entry, a variation on #10, the “Race to 100” game:

(11.5) Play “Odd-‌Even-‌Prime Race.″ Roll two dice. If your token is starting on an odd number, move that many spaces forward. From an even number (except 2), move backward — but never lower than the first square. If you are starting on a prime number (including 2), you may choose to either add or multiply the dice and move that many spaces forward. The first person to reach or pass 100 wins the game.
[Hat tip: Ali Adams in a comment on another post.]

And here’s a question for your students:

  • If you’re sitting on a prime number, wouldn’t you always want to multiply the dice to move farther up the board? Doesn’t multiplying always make the number bigger?

Math Teachers at Play #89 via Mrs. E Teaches Math

Posted on by Denise Gaskins

Math Teachers at Play89From elementary addition to polar coordinates in high school — and all sorts of games, activities, and investigations in between — there’s plenty of fun to be had at this month’s math education carnival. Mrs. E has collected more than twenty great blog posts for us to enjoy:

“Welcome to the 89th edition of Math Teachers at Play (MTaP) Blog Carnival! MTaP is a monthly blog carnival with a collection of tips, games, and activities for teachers of students of all ages…”

Click here to read the whole post at Mrs. E Teaches Math.

Math with Many Right Answers

Posted on by Denise Gaskins
The discussion matters more than the final answer.
The discussion matters more than the final answer.

One of the most persistent math myths in popular culture is the idea that mathematics is primarily about getting right answers.

The truth is, the answer doesn’t matter that much in math. What really matters is how you explain that answer. An answer is “right” if the explanation makes sense.

And if you don’t give an explanation, then you really aren’t doing mathematics at all.

Try This Number Puzzle

Here is a short sequence of numbers. Can you figure out the rule and fill in the next three blanks?

2, 3, 5, 7, ___, ___, ___, …

Remember, what’s important is not which numbers you pick, but rather how you explain your answer.

Possibility #1

Perhaps the sequence is the prime numbers?

2, 3, 5, 7, 11, 13, 17, …

The prime numbers make a wonderful sequence, though it isn’t the one I was thinking of.

Continue reading Math with Many Right Answers