Math is Figure-Out-Able!

#MathStratChat - August 14, 2024

Pam Harris, Kim Montague

In today’s MathStratChat, Pam and Kim discuss the MathStratChat problem shared on social media on August 14, 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  00:01

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

 

Kim  00:06

And I'm Kim.

 

Pam  00:07

This episode is a MathStratChat episode, where we chat about 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 each other's thinking.

 

Kim  00:20

This Wednesday, our math problem was 1.75 times 16. How would you solve this problem? Pause the podcast, solve it however you'd like, and then come back to hear about our strategies. The problem is 1.75 times 16. 

 

Pam  00:35

Alright, Kim, you're up. Go. Okay,

 

Kim  00:37

so I want to think about 1.75 as 1 and 3/4. 

 

Pam  00:43

Mmhm. 

 

Kim  00:44

So, I'm going to say one 16 is 16. And three-fourths of 16 is 12, so 16 and 12 is 28.

 

Pam  00:54

Nice. Because you know three-fourths of 16. Do you think about three-fourths of 16? Or do you just know it? Like, do you think of one-fourth of 16 and find three of them?

 

Kim  01:04

No. No, I think I just know it. 

 

Pam  01:06

You just, you've done... 

 

Kim  01:08

I mean, I might think about fourths. I might...

 

Pam  01:10

Four-fourths. 

 

Kim  01:10

I might think about 4. I might think about 4 because 16 is four 4s to me. So, then three 4s is 12.

 

Pam  01:19

And so, you can find three 1/4s. three 4s. You could also back up 4 from 16 to get to 12.

 

Kim  01:24

(unclear) It would be backup if I was...

 

Pam  01:27

Okay, cool.

 

Kim  01:28

...slowing down. Yeah.

 

Pam  01:28

You stole mine, so I'm going to do something different. 

 

Kim  01:30

Oh, okay.

 

Pam  01:31

So, I'm going to double 1.75. And I got to be honest in the moment, I actually have to double 1.5 to get 3. And then double the extra quarter. So, that's 3.5. Which, now that I see that, I'm like, "Yeah, I knew that." I knew double 1.75 is 3.5.. And I'm going to half 16 to get 8. I'm going to do it again. Double 3.5 to get 7, and half 8 to get 4. And 7 times 4 is 28. 

 

Kim  01:57

Nice. 

 

Pam  01:58

Two different ways of getting 28.

 

Kim  01:59

Yeah, I like it.

 

Pam  02:00

(unclear) Nice. 

 

Kim  02:02

How often do you think that you use Double Halve? Is that like a favorite of yours?

 

Pam  02:07

It depends on the numbers.

 

Kim  02:09

Sure. 

 

Pam  02:10

So, I've written a lot of Doubling and Halving strings. Which means I'm looking for numbers that double nicely. 

 

Kim  02:17

Yeah. 

 

Pam  02:17

And double nicely means that like 3.5 turns into 7. 

 

Kim  02:21

Yeah.

 

Pam  02:22

So, if I see a 3.5, a 4.5. Like 1.75 got me to 3.5. Or a 1.25. Like, there's now numbers that I know that double nicely to get eventually to a nice number. So, like any... Not any. But halves of 10. So, like 5 will double to 10. 2.5 will double to 5, which will double to 10. 1.25 will double. You know, so there are some numbers that if I can get up to 10, bam. Like, then you have a super sweet. So, I think it really depends on the numbers. 

 

Kim  02:54

Yeah, cool. Alright, we can't wait to see what you do every week, so join us on MathStratChat, and let us know how you think about the problems. Comment on each other's strategy while you're there.

 

Pam  03:05

Yeah, and we post these problems on Wednesdays around 7pm Central time. When you answer, tag me and use the hashtag MathStratChat. And then join us here to hear how we're thinking about the problem. We love having you as part of the Math is Figure-Out-Able movement because Math is Figure-Out-Able!