Math is Figure-Out-Able with Pam Harris

#MathStratChat - December 20, 2023

December 20, 2023 Pam Harris
Math is Figure-Out-Able with Pam Harris
#MathStratChat - December 20, 2023
Show Notes Transcript

In today’s MathStratChat, Pam and Kim discuss the MathStratChat problem shared on social media on December 20, 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  00:00

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 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 each other's thinking.

 

Kim  00:21

So, this Wednesday, our problem was 22 times 77. And you guys like the multiplication problems. How did you solve this problem? Pause the podcast. Solve it any way you want, if you haven't solved the yet. The problem is 22 times 77. Solve it, and then come on back to here how we're solving it.

 

Pam  00:38

Bam! Alright. What do you think, Kim? Me or you? Flip a coin? 

 

Kim  00:43

I don't care. 

 

Pam  00:44

Alright, I'm going to go first. I'm going to find twenty-two 77s. 

 

Kim  00:49

Okie doke. 

 

Pam  00:50

So, I'm thinking about 77s. Two 77s is 140 plus 14 is 154. 

 

Kim  00:58

Okay. 

 

Pam  00:59

So, twenty 77s would be 10 times 154.

 

Kim  01:04

Mmhm.

 

Pam  01:04

Which is 1,540. So, 22 of them would add that 154 plus that 1,540, which is 1,600...  I can do this. No, I'm going to have to write it down. I was trying to look across paper. 1,694. Wow, that was wild how I couldn't keep track of that.

 

Both Pam and Kim  01:31

(unclear). 

 

Pam  01:32

Okay, cool. Alright, what do you got? 

 

Kim  01:33

Dang it. I was listening. You did well. Twenty 77s and two 77s were your pieces.

 

Pam  01:41

It's almost like you're proving your were listening. 

 

Kim  01:46

Alright.

 

Pam  01:46

Kim, how are you thinking about the problem? You haven't started thinking about it because you were listening to me.

 

Kim  01:51

I was listening. Okay, so 22 times 77. So, last week, the 11s screamed at you. And so, they're there. And so, I'm writing down 2 times 11 times 11 times 7. And I know this is not going to be as nice as what you ended up with last week because you had a 2 times 5, which was really nice. So, now I've written down 121 times 14. So, I did the 11 times 11 to get the 121. And then, the leftover factors of 2 times 7 to get 14. Yeah. And I didn't want to do a whole lot for that. So, I'm still committed a little bit into the problem. I haven't like taxed my brain quite yet. But 121 times 14. 121 times 10 is 1,210. 1,210. And really, 121 times 4 is not bad. So, I thought it would be a little  clunkier than it is. But I got 1,210 plus 484. (unclear).

 

Pam  02:51

I think you just think about 4 times 121. Not too bad. It's just 484. 

 

Both Pam and Kim  02:55

Yeah.

 

Kim  02:55

You can double double.

 

Kim Montague  02:57

I mean, I didn't. I just thought 400, and then 80, and then 4. 

 

Kim  03:01

Mmhm.

 

Pam  03:01

Yeah, yeah.

 

Kim  03:02

So, I also got 1,694. (unclear).

 

Pam  03:06

Add those together. 

 

Both Pam and Kim  03:06

Mmhm. 

 

Pam  03:07

Nice. There was a part of me that was wondering about the difference of squares. But I didn't get very far because I was actually listening to you.

 

Kim  03:20

(unclear) So, they're kind of worth 50? 

 

Pam  03:23

Yeah, like.

 

Kim  03:25

That would be kind of far away. (unclear) it's not bad, I guess.

 

Pam  03:28

Is that is that 50 minus 28? 

 

Kim  03:31

Mmhm.

 

Pam  03:32

And 50 plus 27?

 

Kim  03:34

27. Mmhm.

 

Pam  03:36

So, that would be... I would have to know what 50 times 50 is, which is 2,500. And then, I have minus 28 of them plus 27 of them is minus 150. And then... Ooh, but then I have to know 28 times 27. Nah. 

 

Kim  03:52

Nah. Not worth it. 

 

Pam  03:53

So, either I didn't choose a nice, perfect square to think about or a difference of squares. I'll go play with that. So, if you guys are a perfect square person who likes to play with that difference of squares thing, feel free to shoot out what a better difference of squares might have been for that problem.

 

Kim  04:11

Yeah.

 

Pam  04:12

Yeah. 

 

Kim  04:12

And it's okay to want to do a strategy, and then...

 

Pam  04:15

Back out of it.

 

Kim  04:16

Back out, and say...

 

Pam  04:17

I'm backing out. I'm backing out, Kim. I'm backing out.

 

Kim  04:19

Totally legal. Alright, everyone. We can't wait to see what you're thinking. Represent your thinking, take a picture of your work, share it with us, and tell the world on social media how much you love MathStratChat. While you're there, check out what other people did.

 

Pam  04:33

Oh, I like how you just said, "Tell people how much you love MathStratChat." I like that.

 

Kim  04:37

We want everybody to play MathStratChat!

 

Pam  04:39

Bam, right? Right? Wouldn't that be good? That would be excellent. And tag me while you're there, and use the hashtag MathStratChat. And then, check out our next MathStratChat problem that we'll post every Wednesday around 7pm Central time, and then come back here to hear what we're thinking about the problem. We love having you as part of the Math is Figure-Out-Able movement. Thanks for spreading the word that Math is Figure-Out-Able!