A
great friend of mine (who is a math specialist in a school district) and I met
late last week for lunch. During our visits, we often discuss different
mathematical problems and new things we have learned along the way. This time was
no different. After getting caught up a bit, Jenny asked me about a problem she
had seen where people were asked to mentally do the problem 600 ÷ 48. Jenny explained
that in what she read, there were 3 common ways that folks attacked that
problem. How would you do 600 ÷ 48 mentally? What answer do you get? How do you get it?
True
confessions....that one stumped me. It wasn't that I couldn't get it, but on-the-spot pressure blocked me from moving forward. I knew 10 something or other.
Jenny
shared with me 3 common ways that people approached this problem mentally that were mentioned.
There are a ton more, but these the three methods below were mentioned in the book.
600 ÷ 48
- Think of the problem as 100 ÷ 8
- Think of the problem as ½ of 100 ÷ 4
- Think of the problem as 600 ÷ 50 + ½
Is
600 ÷ 50 an easier problem,
sure. That gets you an estimate but where does that darn + ½ come from? I wanted to be able to provide
Jenny with a visual model of what that might look like because to be honest, if
we could figure that out, it would make it a much much easier mental math
problem.
The next morning while my husband David and I were walking. I was thinking out loud and said "ohhhh...I think that would work." He asked what I was talking about and I told him I was working on a math problem. Not impressed. We didn't talk about it any more. When we arrived home, I put my ideas on paper and created the video to send to Jenny explaining my thinking.
BUT
HERE IS THE KICKER!!
As
I spent my weekend working on math problems, my wonderful husband David simply shakes his head. He is an artist and musician at heart and often
doesn't see the beauty of math as I do. He tolerates my endless talking about
an "I love math generation" and at least acts interested when I get going on math problems. He
is a self-proclaimed math hater. In all honesty, that makes me very sad.
So
I posed this problem to David. 600 ÷ 48. (He had not seen
what I had been working on.) I asked him to share how he would attack that
problem. You know what he said.....
"I'd
take 600 ÷ 50 and get 12. But I
know that is 2 too many in each group so I have to do something with the
2's."
HE
IS BRILLIANT MATHEMATICALLY! Why didn't I just ask him (the self proclaimed
math hater) to explain the darn thing to me! Well Mr. Smarty Pants, what about
those 2's?
Below
is the visual model of what happens in that problem and a quick visual
explanation of the other 2 methods as well.
My
point is this. In order to become an "I love math generation" we need
to foster creativity in thinking instead of forcing memorization and
algorithms. I think many people out there who hate math only hate math because
of their school experience. After this experience with David, I think that is why he hates math.
We can change that. We MUST change that!
We can change that. We MUST change that!
I
love you David!
NOTE: The video is "raw". If I was producing these professionally I would clean up some of my errors in how I say things mathematically. Perhaps I will do that someday. In the end you see I say "divide by a half" when actually I meant "divide by 2". Because I know Jenny knew what I meant, I didn't fix it. You'll get the point.
NOTE: The video is "raw". If I was producing these professionally I would clean up some of my errors in how I say things mathematically. Perhaps I will do that someday. In the end you see I say "divide by a half" when actually I meant "divide by 2". Because I know Jenny knew what I meant, I didn't fix it. You'll get the point.