Math is Figure-Out-Able with Pam Harris

#MathStratChat - November 2, 2022

November 02, 2022 Pam Harris
Math is Figure-Out-Able with Pam Harris
#MathStratChat - November 2, 2022
Show Notes Transcript

In today’s MathStratChat, Pam and Kim discuss the MathStratChat problem shared on social media on November 2, 2022. 


Note: It’s more fun if you try to solve the problem, share it on social media, comment on others strategies, before you listen to Pam and Kim’s strategies.


Check out #MathStratChat on your favorite social media site and join in the conversation.

Pam Harris:

Hey fellow mathematicians. Welcome to the podcast where Math is Figure-Out-Able. I'm Pam Harris.

Kim Montague:

And I'm Kim Montague.

Pam Harris:

And this episode is a MathStratChat episode. What is MathStratChat? Y'all every Wednesday evening, I throw out a math problem to the world on Twitter, Facebook and Instagram. People all over chat about the strategies they use. It is super cool to see everyone's thinking.

Kim Montague:

Yeah, it's definitely one of my favorites. Okay, this Wednesday, our math problem was five fourths of 11. How would you solve this problem? Go ahead and pause the podcast and solve it however you want. Remember, the problem is five fourths of 11 solve it and then come back to hear how we solved it. Go.

Pam Harris:

Alright, y'all, Kim, I'm gonna go first. Is that okay?

Kim Montague:

Okay. Yep.

Pam Harris:

Okay, so five fourths of 11. I'm just somehow dying to use five fourths of one. Oh, so I'm kind of thinking about five fourths of 10 and then five fourths of one. That's kind of where my brain went. And to get five fourths of 10, I thought about four fourths of 10. Like the all of 10, four fourths of 10, plus a fourth of 10, one fourth of 10, I just know is two and a half. That's just like half of five, half of half. So five fourths of 10, I think is 12 and a half. Does that track? And then all I have to do is, so if that's five fourths of 10, then all I have to do is add five fourths of one five fourths of one is just five fourths. And I can think of that as five fourths, or one and a quarter. It's five quarters. And so I've got 12 and a half plus one and a quarter. That's 13 and three quarters. 13.75. Nice. Is that okay?.

Kim Montague:

Yeah, I like. When I started to write down, I recognized what you were going to do. I thought maybe you were going to do the five fourths of one first and then scale up to get to ten.

Pam Harris:

Oh, no, I did think of that.

Kim Montague:

So I was like jarred a little bit. I was like, "Ooh, okay. I like." All right. Okay.

Pam Harris:

Now you make me want to think about that. So it would be the one and a quarter times 11?

Kim Montague:

Well, you did the five fourths of 10 and the five fourths of one. So I thought you were going to do five fourths of one and add to that five fourths of 10. But get the five fourths of 10 from your answer of five fourths of one.

Pam Harris:

But do you see what I'm saying? I'm thinking of, now you've got me thinking about five fourths of one. Can I scale that if I know five fourths of one is one and a quarter, then five fourths of 10? Wouldn't that or 11, would I multiply one of the quarter times 11?

Kim Montague:

Yeah.

Pam Harris:

Is that right? Is that right?

Kim Montague:

It's kind of funky. But yeah.

Pam Harris:

So that'd be 11 plus 11 quarters. Which is a little funky. 12 quarters is three. So two and three quarters. Yeah. And there's a 13 and three quarters. Sorry, I just couldn't let that go.

Kim Montague:

I understand. Sometimes you can't.

Pam Harris:

Hey, um, you find it interesting that when I scaled that up, I drew a ratio table. I don't know. Somehow that's just really...

Kim Montague:

Oh, yeah. Great model.

Pam Harris:

Really helps me think through that. Okay. What did you do? Sorry to take up all the time.

Kim Montague:

So I, um, so. I'm not in love with my strategy. And I'll tell you, that's okay. Because it doesn't always happen on the first go round.

Pam Harris:

Yep.

Kim Montague:

So I did one fourth of 11. And to get a fourth of 11, then I thought, half of 11 is five and a half. And so then half of that would be five and three quarters.

Pam Harris:

Wait, wait. Five and a half...

Kim Montague:

I'm sorry, did I say five and three quarters?

Pam Harris:

I don't even know.

Kim Montague:

Two or three quarters.

Pam Harris:

Two and three quarters. Is 1/4 of...

Kim Montague:

Is 1/4 of 11 is 2.75.

Pam Harris:

Gotcha. Okay.

Kim Montague:

Okay. So then I was like, Oh, sweet. All you got to do is scale up by five. But that left me with 2.75 times five. And that's where I was like, uh, I guess what am I going to do? But when I looked back, I realized that I could have done 2.75 times 10, which will be 27.5. And then half that to get 13.75.

Pam Harris:

Nice.

Kim Montague:

So a couple of different things to think of.

Pam Harris:

Can I totally tell you what I'm thinking of?

Kim Montague:

Yeah.

Pam Harris:

When you said 2.7 to five times five.

Kim Montague:

Yeah.

Pam Harris:

I was like, but that's, we could double half.

Kim Montague:

Yeah.

Pam Harris:

Because if you double the five, oh, that's not as nice as I was thinking. Hey, that's funny. I actually was gonna double both of them. But then I would have a five by four. So that's not as nice. Somehow in my head I was able, I was gonna like, because you'd already halved the five and a half to get the 2.75. So I was just like, "Just double it to get 5.5." But then you would have had to have halved the five and that's not as nice. Nevermind, mine's not as nice. There's a don't do.

Kim Montague:

Well, that's what we do, right? You start on the strategy and then you back out and say, "No, I don't wanna do that."

Pam Harris:

Not that. Yeah, I was gonna double double instead of double half. So close and yet so far. Nice. I like it.

Kim Montague:

All right, listeners. We can't wait to see your strategies. I wonder if it was like one of ours or something entirely different. We'd love it if you'd represent your thinking and take a picture of your work or screenshot on your phone. Tell the world on social media. And while you're there, comment on what other people did.

Pam Harris:

And tag me on Twitter @PWHarris or Instagram, Pam Harris_math or Facebook, Pam Harris, author, mathematics education, and make sure you use the #MathStratChat. So make sure you check out MathStratChat problem every Wednesday at 7pm Central time and then pop back here to hear how we're thinking about the problem. Y'all we love having you as part of the Mathis Figure-Out-Able movement. Let's keep spreading the word that Math is Figure-Out-Able.