Math is Figure-Out-Able!

#MathStratChat - October 18, 2023

Pam Harris

In today’s MathStratChat, Pam and Kim discuss the MathStratChat problem shared on social media on October 18, 2023. 


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.

Twitter: @PWHarris

Instagram: Pam Harris_math

Facebook: Pam Harris, author, mathematics education


Want more? Check out the archive of all of our #MathStratChat posts!




Pam  00:01

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

 

Kim  00:07

And I'm Kim Montague. 

 

Pam  00:08

And this episode is a MathStratChat episode where we talk about the problem I've thrown out on social media on Wednesday evening, and where people from all around the world chat about the strategies they use. We love seeing everyone's thinking.

 

Kim  00:23

Okay. Also, this Wednesday our problem was 14 times 75. How are you thinking about this problem? Pause the podcast. Solve it however you'd like. Problem is 14 times 75. Solve it, and then come on back. (unclear).

 

Pam  00:38

Alright, Kim. What are you thinking about? I want you to go first.

 

Kim  00:42

Okay. You know, I didn't do percents last week, and it made me a little sad, so I'm going to go percents today. 

 

Pam  00:51

Do it! 

 

Kim  00:52

Because I like it. So, 75% of 14, I don't just know off the bat. But I do know 75% of 10 is 7.5. And I know 75% of 4 is just 3. So, together, that would be 10.5. And then, I need to scale up because we're talking about percents. So, 75 times 14, is 1,050.

 

Pam  01:20

Interesting. Hey, I'm going to slow you down just little bit. How do you know that? 75% of 10 is 7.5? Maybe that's too easy, but.

 

Kim  01:27

I guess because 75% of 1... No, I didn't think about the 1 at all. I guess it was like if I had $10.00, what would 75% of it be? I'd get $7.50. I don't if I.

 

Pam  01:39

Sure. Or 75% of 100 is 75, so (unclear). 

 

Kim  01:42

Yeah.

 

Pam  01:43

But you probably didn't think about any of that. Yeah. 

 

Kim  01:44

No, I didn't think about 100 or 1. 

 

Pam  01:46

And then, how do you know that 75% of 4 is 3? Is that too easy too? Yeah.

 

Kim  01:52

1, 2, 3, 4. I need 3 of them.

 

Pam  01:54

3 out of the 4? 

 

Kim  01:55

Yeah.

 

Pam  01:55

Alright, you have 4. You need 3 out of 4. That is 75%. Cool. Alright. So, I was messing a little bit with the fact that two weeks ago, we talked about 12 times 75, and we got 900. And then, last week, we talked about 16 times 75, and we got 1,200. So, 12 and 16. And this time, we're talking about 14 times 75. So, if I know that 12 times 75 is 900, and 16 times 75 is 1,200, and 14 is smack dab in the middle of 12 and 16, then I asked myself what is smack dab in the middle of 900 and 1,200? 

 

Kim  02:34

Nice. 

 

Pam  02:35

So, they're 300 apart. Half or 300 is 150. And so, 900 and 150 is also that 1,050. 

 

Kim  02:43

Nice. 

 

Pam  02:43

Is that alright?

 

Kim  02:44

I like it. Yeah. I like a lot. 

 

Pam  02:46

Cool. 

 

Kim  02:47

Alright, so we can't wait to see your thinking what strategy you chose.

 

Pam  02:51

(unclear). I'm so sorry. (unclear)

 

Kim  02:53

What, you want to say more? (unclear).

 

Pam  02:54

I do kind of just a little bit. Well, because I was thinking about the... Do you remember last week where I quadrupled 75? 

 

Kim  03:00

Yeah.

 

Pam  03:00

So, surely that's got a scream to somebody here that I got 10 plus 4 times 75. 

 

Kim  03:07

Well, that's what I did. Kind of.

 

Pam  03:09

Well, not in the same way though. 

 

Kim  03:11

Yeah. (unclear).

 

Pam  03:13

That's true. I hadn't thought about it. Yeah. Well wait.

 

Kim  03:18

I mean, I did 75% of 10 and 75% of 4, so I split the 14 in the same way.

 

Pam  03:22

True, but you ended up adding 7.5 and 3, and I'm going to add 750 and 300. Yes, it's like same place value relationships, but not as I was thinking about them...until I looked at them after the fact. Anyway, sorry to interrupt. Keep going.

 

Kim  03:38

No, it's good. Oh, people. It's good times here. Will you represent your thinking, and take a picture of your work, and tell the world on social media? While you're there, check out what other people did and comment on their thinking.

 

Pam  03:51

We love it when you comment on other people's thinking. It helps people feel heard and seen, and so then they spread the word, and then we just keep spreading the word. It's awesome. While you're there, tag me on Twitter, X thing, @PWHarris. Or Instagram, Pam Harris_math. And Facebook, Pam Harris, author mathematics education. And use the hashtag MathStratChat. Make sure you check out our next MathStratChat problem that we'll post every Wednesday around 7pm Central Time, and then come back here to hear how we're thinking about the problem. We love having you as part of the Math is Figure-Out-Able movement. Let's keep spreading the word that Math is Figure-Out-Able!