In a previous post, I wrote about how poor math is so maligned by this culture.
In my post, there was something I wanted to get to, but my train of thought went a different direction. Fortunately, trains of thought can circle back around, and here we are again.
Earlier today, someone on facebook posted a video about an interesting method of multiplication that I hadn't seen before. Ooooh!
When I showed it to one of my kids, he showed me a different way that he knew. Oooh, again!
It reminded me of what I had wanted to say before: that one of the things I particularly enjoy about math is that much of the time, there are lots of choices in how to approach anything you need to find out. I've seen people get all caught up in being frustrated about knowing what to do, or which equation to use, but the truth is, much of the time, you can choose whichever method you are happiest or most comfortable with.
Don't like percentages? Use decimals. Or fractions.
Rearrange things so that you can make more sense of the problem.
Convert things if it makes it easier.
I love it!
So when I saw these different methods of multiplication today, I was delighted. I LOVE learning different ways of approaching the same thing. For one thing, it's fun. For another, different people are attracted to different methods, different techniques, different styles. The more you know, the more likely one (or more) will resonate with you.
So. Check these out.
First, from the Khan Academy, a video showing the way people are typically taught to multiply.
Then, a different way of looking at the same method. It's shown as a "trick," but it's basically the same, just not written out the same way.
Next, the method someone posted on facebook this morning, as the "Japanese method" but I've also seen it called the "Mayan method."
Here is another version of that method. It fundamentally works the same way, but the graphical representation is quite different, and, I think, lovely.
Now, the method my son showed me this morning, called the "lattice method."
I haven't been able to find a good video of multiplying with an abacus, but there must be one. I'll keep looking.
This all reminded me of something my mother was fascinated with when I was younger, that she called "fingermath," but it's more formally called chisenbop. Haven't found any good videos for that, either, but there is a page with some information on it here.
Wasn't that fun?
Do you know any other methods? I'm sure there are more.
None of these methods are the same as how I multiply in my head, for example.
Facility with manipulating numbers makes a lot of things much easier. Play with them. Try these methods out and see, first of all, which you like, and then, see if you can explain to someone why and how they work.