In today’s MathStratChat, Pam and Kim discuss the MathStratChat problem shared on social media on February 7, 2024.

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 00:00

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

Kim 00:06

And I'm Kim.

Pam 00:07

And this episode is a MathStratChat episode, where we chat about our math strategies. Every Wednesday evening, I throw out a math problem on social media, and people from around the world chat about the strategies they use, and comment on others thinking. Hey, Kim

Kim 00:22

Hi.

Pam 00:23

Hey, Kim, you're up.

Kim 00:24

Oh, my gosh. Did I say, "I'm Kim" or did I totally (unclear).

Pam 00:28

No you did. You said, "And I'm Kim." Oh, my.

Kim 00:30

I think I hear that, and I just go with that one. Okay, so we got a problem for you. It was Wednesday. Oh, heavens.

Pam 00:38

Hey, Kim, what was our problem (unclear)?

Kim 00:39

don't know. 45% of 66. 45% of 66. We're curious how you would solve the problem. Pause it, solve it, come on back to hear how we're going to solve. I

Pam 00:50

Bam. Alright, Kim, I'm starting today just to give you a chance to breathe. Okay, I'm going to think about 45% of 66 by thinking about 100% of 66. Which is 66. To get 50% of 66. Which then would be half of 66. So, that's 33. And then, I'm going to scale that down to get 5%. So, if 50% is 33, then 5% is divided by 10. So, divide 33 by 10, and I get 3.3. So, now I've got 50% and 5%. I'm going to subtract that to get 45%. So, 33 minus 3.3 is 30, 29.7.

Kim 01:33

29.7. Okay.

Pam 01:37

Does that sound right?

Kim 01:38

Yeah, so I like your (unclear).

Pam 01:41

We would call that kind of a Five is Half a Ten strategy.

Kim 01:43

Yeah.

Pam 01:43

Yeah.

Kim 01:43

I like you're 50%. That's really nice because the 45%. You, last week, did use the commutative property. And I don't know that I actually love that for 66% of 45. But I actually wonder about 66% of 50. Do I like that? (unclear). I'm thinking out loud. 66% of 100. (unclear).

Pam 02:08

Okay.

Kim 02:09

What would 66% of 100 be? Well, that would be 66.

Pam 02:13

Yeah.

Kim 02:14

So, 66% of 50 would be 33. 66%... Oh, I'm a liar. 66% of 100 would be... What is to 66% of 100? Good heavens. I'm still thinking about not paying attention. And then, I found out I was drifting my brain when you were talking too, and I realized, "Oh, she's doing what I wanted to do." Alright. 66% of 100 is 66.

Pam 02:42

Sure enough.

Kim 02:43

And 66% of 50 is 33. So, now I need 66% of 5, so that I could backup to get to the 45. So, 66% of 5 would be 3.3. So, then I'm going to do 33. Which was (unclear). 66% of 50 minus 66% of 5. So, 33 minus 3.3 gives me 29.7.

Pam 03:16

Bam!

Kim 03:17

And that is thinking on the fly people.

Pam 03:18

That's awesome.

Kim 03:19

No planning here.

Pam 03:20

So, it's super interesting because I found 100% of 66, 50% of 66, 5% of 66.

Kim 03:28

Yeah.

Pam 03:28

You found 66% of 100, 66% of 50, and 66% of 5. And actually we ended up with the same numbers.

Kim 03:36

Yeah.

Pam 03:37

But we thought about it completely differently. That's super interesting. Yeah, cool. I do kind of want to run with the communitive property, if you don't mind really (unclear)?

Kim 03:45

Sure, yeah.

Pam 03:46

I was going to find 66% of 45. I'm thinking about that like... Let me think for a second. I'm thinking about trying to find 6% of 45. And if I can find 6% of 45, then I also have 60% of 45. So, I'm going to find 100% of 45. 100% of 45 is 45. To get 50%, which is half of that, so that's 22.5 is 50%. And 10% of 45. Yeah, I'll finish it if you want me to, but I've already (unclear)...

Kim 04:28

No.

Pam 04:28

...if I'm not loving it.

Kim 04:29

Yeah, I also am... I will not finish it. But I'm also loving the factoring, the 45% and the 66%, because there's (unclear) like 9 and 11 in there, which you know is (unclear).

Pam 04:43

Well, now you make me want to play with that because...

Kim 04:44

Okay, well, let everybody play with it. We won't share it.

Pam 04:47

Ah, so you're factoring 66 into something.

Kim 04:50

Mmhm. And $0.45 in my mind. 45%, $0.45 into something.

Pam 04:57

And then, kind of messing from there. Alright, so we're just going to kind of leave people maybe to mess with either of those.

Kim 05:02

Yeah.

Pam 05:03

The other thing that I'm... I hear one more thing to mess with. For the 66, I wonder if I would have found 3% of 45. That one I can actually hang on to because it's like 3 times 45, and then scale. And then, double that to get the 6%. Then, times 10 to get 60. And then, add the 60 and 6. I didn't actually do it, but that could be a road that I could have gone down.

Kim 05:26

Yeah, super fun.

Pam 05:27

Alright, lots of fun. Cool.

Kim 05:29

So, we'd love for you to share your strategy. Maybe it's like one of these ones we mentioned. Represent your thinking, take a picture, and tell the world. Let's get everybody playing MathStratChat.

Pam 05:39

Yeah, and use the hashtag MathStratChat and make sure you check out our next MathStratChat problem that we'll post Wednesdays around 7pm Central time, and then come back here to hear how we're thinking about the problem. Thank you for being part of the Math is Figure-Out-Able movement!