Math is Figure-Out-Able!
Math teacher educator Pam Harris and her cohost Kim Montague answer the question: If not algorithms, then what? Join them for ~15-30 minutes every Tuesday as they cast their vision for mathematics education and give actionable items to help teachers teach math that is Figure-Out-Able. See www.MathisFigureOutAble.com for more great resources!
Math is Figure-Out-Able!
#MathStratChat - December 20, 2023
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
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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!