How to Conquer the Times Table, Part 1

Photo of Evil Erin times 5 (and dog times 2), via flickr.

Perhaps the biggest challenge for any middle-elementary math student is to master the multiplication facts. It can seem like an unending task to memorize so many facts and be able to pull them out of mental storage in any order on demand. Too often, the rote aspect of such memory work overwhelms students, eclipsing their view of the principles behind the math. Yet rote memory is not enough: A student may be able to recite the times tables perfectly and still be reduced to counting on fingers in the middle of a long division problem.

We will use the world’s oldest interactive game — conversation — to learn the multiplication facts one bite at a time. But first, let’s take some time to think about what multiplication really means.

Continue reading How to Conquer the Times Table, Part 1

More Than One Way to Solve It


Photo by Eirik Newth via flickr.

In a lazy, I-don’t-want-to-do-school mood, Princess Kitten was ready to stop after three math problems. We had gotten two of them correct, but the last one was counting the ways to paint a cube in black and white, and we forgot to count the solid-color options.

For my perfectionist daughter, one mistake was excuse enough to quit. She leaned her head against me as we sat together on the couch and said, “We’re done. Done, done, done.” If she could, she would have started purring — one of the most manipulative noises known to humankind. I’m a soft touch. Who can work on math when there’s a kitten to cuddle?

by tanjila ahmed via flickr

Still, I managed to squeeze in one more puzzle. I picked up my whiteboard marker and started writing:


Continue reading More Than One Way to Solve It

Updated Free Math from Dover

If you tried to get any of the Dover samples I linked to last month, and instead you got Dover’s home page, I’m sorry! Apparently the sampler links aren’t stable. 😦 I’ve corrected most of them and deleted those I couldn’t correct, so everything works as of tonight:

I found permanent links for several of the books, but a few of them are still sampler links — especially the children’s books — and those will probably go AWOL as the others did. So if you were planning to download one of the sample pages, be advised to do it soon.

howtosolveproblemsWant to help your kids learn math? Claim your free 24-page problem-solving booklet, and sign up to hear about new books, revisions, and sales or other promotions.

Math Teachers at Play #41 via I Hope This Old Train Breaks Down…

The new Math Teachers at Play blog carnival has plenty of fun for math fans of all ages:

Willkommen! Welcome to the Math Teachers at Play blog carnival! Whether you are a teacher, homeschooler, parent, or a math enthusiast interested in general discussions about mathematics, there is a little bit of something for everyone here. Some of these links came as direct submissions by bloggers, and the others came from my Google Reader.

To start, here are some fun facts about the number 41:

  • Starting with 41, if you add 2, then 4, then 6, then 8, etc… you would get a string of 40 prime numbers in a row!
  • 41 is also a Centered Square Number, which means that it is the sum of two consecutive squares — 4^2 and 5^2, in this case. Can you figure out how this picture relates to the Center Square Numbers, and use the picture to explain why all Center Square Numbers are 1 (mod 4)?

Go read the blog carnival at I Hope This Old Train Breaks Down…

Math History Ideas, and Congrats to Giveaway Winners

Congratulations to Fibonacci giveaway winners Ken, Judy, Katie, Penney, Rachel, and Charlotte! 🙂 For everyone else, the comments on the Fibonacci post are full of great ideas for combining math and history in your teaching. Readers recommended several books — some of which are among my family’s favorites, and others I’d never heard of (now waiting in my library loan queue). Thank you to everyone who participated in the contests!

Still Time to Enter

You still have a few days to enter my giveaway contest for Keith Devlin’s new e-book, Leonardo and Steve: The Young Genius Who Beat Apple to Market by 800 Years, and his latest print book, The Man of Numbers: Fibonacci’s Arithmetic Revolution. The number of entries so far is low enough that you have very good odds of winning!

To join in the fun, just follow the instructions at this post:

howtosolveproblemsWant to help your kids learn math? Claim your free 24-page problem-solving booklet, and sign up to hear about new books, revisions, and sales or other promotions.