Friday, September 6, 2013

Multiplication tables

So how is it that a kid can make it all the way to the ninth grade and still not have memorized the table? It's on the wall of every elementary classroom - how can you possibly not learn it?


  1. Don't you know when you're not hungry and you get into the kitchen? Do you notice all the food?

    How can many of them not learn that (a+b)² is not a²+b²? That you can't cancel the a's in (a+2)/(a+3)? And so it goes...

  2. If it doesn't turn you on, why would you focus on it?

    I just read The Book of Learning and Forgetting, by Frank Smith. He makes a sharp distinction between memorizing and learning. I think knowing those multiplication facts is vital to doing lots of interesting mathematical work, but students will only know them if they felt engaged by the ideas at some point. Maria Droujkova is doing an online course called Wow! Multiplication that might help participants find a way to approach learning these with joy.

  3. I teach community college and they still don't know them.

  4. Sue VanHattum, you would focus on it because it's a required part of the curriculum, and your teacher provided you with opportunities to practice on a frequent basis and expected you to improve. There are not many items in the standard K-8 curriculum that I can justify saying every child must learn, but the multiplication tables is certainly one of them. Framing this task as essential to shopping, carpentry, cooking, and quite a number of recreational activities makes it easier. But you have to memorize those facts before you can understand their usefulness. Can't wait for students to want to learn them on their own.

  5. Some kids will learn the multiplication table without a dedicated effort, but most require that dedicated effort. Many schools today are using either the spiraling method or discovery method of teaching math, and these methods spend little or no time on memorizing the math facts. I had a discussion about this with one teacher who told me her students didn't need to memorize the math facts because 80% of her students memorized most of them over time. All I could do is wonder about how well those 80% really knew their facts, and what about the other 20%?

  6. I memorized the multiplication tables in 7th grade to pass the timed test.

    I LEARNED the multiplication tables as a grownup after my dad kept saying that I was getting to be an idiot because of my calculator usage (my words, not his - he would kindly and firmly admonish my calculator usage).

    When I realized that I was actually typing in 7 x 8 into the calculator (every time) I decided it was time to stop.

    I still struggle with the 9's (despite everyone trying to get me to use the "finger trick"), but I'm doing better.

    And I'm engaged with it - it's a point of pride to show my daddy that I DO indeed know them and don't have to rely on the devil box.

  7. I my kids love it