Math is Figure-Out-Able!

#MathStratChat - April 10, 2024

Pam Harris

In today’s MathStratChat, Pam and Kim discuss the MathStratChat problem shared on social media on April 10, 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 mathers! Welcome to the podcast where Math is Figure-Out-Able. I'm Pam Harris. 

Kim  00:06
And I'm Kim Montague. 

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 each other's thinking.

Kim  00:19
Okay, so this Wednesday, our math problem was 34 times 46. How would you solve this problem? Pause the podcast. Solve it any way you want. The problem is 34 times 46.

Pam  00:33
Bam. Alright, I'm going to go first. 

Kim  00:35
Okie doke.

Pam  00:36
Because.  And this problem...

Kim  00:38
Because. Because I want to.

Pam  00:41
Because I want to. Pretty much. This problem, my first instinct when I look at 34 times 46, is "Yuck."

Kim  00:48
Yeah. 

Pam  00:48
So, none of the usual culprits are jumping out to me, except I'm noticing that they are both 6. Both numbers, 34 and 46, are 6 away from 40. So, I'm thinking about writing this as 40 minus 6 for 34 times the quantity 40 plus 6 for 46. So, 40 times 40 is 1,600. The insides add out, and then I've got negative 36. So, 1600 minus 36. Play a little I Have, You Need is 15. I got to think. 64. 

Kim  01:24
Mmhm. Mmhm.

Pam  01:25
Yeah, 64. 36,64. Yep, yep. Alright. What are thinking about? 

Kim  01:30
What did you just say? 

Pam  01:32
1,564.

Kim  01:33
Oh, I thought you said 3,664. You were talking about the partner. I was like, "Mmm..." Okay, I'm with you now.

Pam  01:40
Read my mind. Don't. Don't. It's a scary place in there.

Kim  01:45
Oh, gosh. Okay, I'm going to be honest with you. We could talk about some partial products. I mean, I could say like 34 times 50 and do a little bit Over. But sometimes there's a problem where it just screams, like that is so overwhelmingly good. It's like when we talk about the plus 99. Like, plus 99 is plus 100 minus 1. We wouldn't really. I mean, kids could do whatever they want, right? But we would so heavily nudge the Over strategy for plus 99. And I think this is a prime example of a problem that really heavily we would nudge difference of squares. Now, if that's not, you know, where you're at age wise, then okay. But anything less than that at this point for me is like ho hum. Do I have to have one? No. I don't... I mean... There are things you could do. But.

Pam  02:48
Well, let me tell you what I started.

Kim  02:49
Let's highlight how great it is. 

Pam  02:51
It's so good.

Kim  02:52
Yeah.

Pam  02:52
I started playing because I just like if I didn't have the difference of perfect squares, what could I do? Or the difference of squares. I shouldn't have said perfect. The difference of squares. I could have thought about 34s. 

Kim  03:06
Yeah. 

Pam  03:06
And I could find two 34s, double that to get four 34s. Add those together to get six 34s. 

Kim  03:13
Yeah. 

Pam  03:14
Scale up the 4 times 40. And I'm almost there. That would be 1,360. And then, I could add the 40 and the 6 together. 

Kim  03:22
Yeah.

Pam  03:23
I could do that. And that's maybe what I would. You know, if I wasn't already. Because, you know, we might have kids that are fourth, fifth grade that they haven't really care about. 

Kim  03:30
Sure, sure, sure.

Pam  03:31
Yeah. Yeah. Cool.

Kim  03:33
Alright

Pam  03:33
Alright.  We can't wait to see what you do each week. Join us on MathStratChat, and let us know how you think about the problem. And comment on each other strategies. 

Kim  03:42
Yeah, we post the problems on Wednesdays at 7pm Central. So, when you answer tag Pam and use the hashtag MathStratChat. Then, join us to hear what we're thinking about the problem. We love having you a part of the Math is Figure-Out-Able movement!