# 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 - April 3, 2024

In today’s MathStratChat, Pam and Kim discuss the MathStratChat problem shared on social media on April 3, 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! Does that sound right mathers? Am I saying that right? Mathers? Yeah?

**Kim **00:09

You emphasize it more than I would, but I think it's fine.

**Pam **00:12

Alright. I'm Pam Harris.

**Kim **00:14

And I'm Kim Montague.

**Pam **00:15

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 **00:27

So, this Wednesday, our problem was 25 times 35. How would you solve the problem? Pause the podcast, and solve it however you want. The problem is 25 times 35. Go.

**Pam **00:42

Alright, Kim. I'm going to go first this time. So, after last week's problem 16 times 24, there were some strategies on social media that got me thinking about how I could have solved that one, and man it is making me think about it for this one. So, 25 times 35, I'm going to write as 30 minus 5. That's 25. Times 30 plus 5, that's 35. And once I do that, I can get a little high school algebra-ish here, where I can sort of then just use the distributive property. So. 30 times 30 is 900. Negative 5 times 30 and positive 5 times 30, add to 0. And then, negative 5 times positive 5 is minus 25. So, now I end up with 900 minus 25. Play a little I Have, You Need 875. Bam! Ooh.

**Kim **01:33

I like it.

**Pam **01:34

That is sweet. What do you got?

**Kim **01:36

I was thinking about an Over strategy.

**Pam **01:40

Mmm, mmhm.

**Kim **01:41

So, I was thinking 25 times 40, which is 1,000. Because I know 25 times 4 is 100. So.

**Pam **01:48

Oh, nice.

**Kim **01:49

Scaled up by 10 is 1,000. And then, I've gone over by five 25s, which is 125. So, then I wrote down 1,000 minus 125. And same as you with I Have, You Need, then I land at 875.

**Pam **02:06

Kim, I like that. I like that a lot. I would not have gone there today. The other place I was going to go, which I don't know if I have to play it out. But I was thinking about a fourth of 35. I thought you were going to do that.

**Kim **02:18

You know, actually, that was the first thing that I thought about doing.

**Pam **02:23

Yeah.

**Kim **02:24

But it wasn't the operator meaning. It wasn't a fourth of 35. But I thought about Doubling and Halving. So, different strategy, but would have gotten me at the same place, where I was like, "Do I really want to find a half of 17.5.?" And if I had... So, maybe that wasn't the same. If I had done a fourth of.

**Pam **02:43

You just did that really fast. So, if you had 25 times 35, you could double the 25 to 50, halve the 35 to 17.5. That's why you were talking about, then you could double the 50 to 100. And then, you'd have to halve 17.5.

**Kim **02:55

Yeah. And it could be done because I can thought about 16 and 1.5. But I kinda was like, "Nah, I'm feeling lazy." So, I went with something that took less thinking in that moment. And that's perfectly legal. Sometimes you want to challenge yourself. Sometimes you don't.

**Pam **03:10

Okay, and so I was thinking about a fourth of 35 as a fourth of 36.

**Kim **03:15

Yep.

**Pam **03:16

And then, backing up from there. But I also got lazy and decided to just do. (unclear).

**Kim **03:22

It's one of those days. Okay, every week, we cannot wait to see what you do with MathStratChat, so join us and let us know how you think about the problems, and be super cool and comment on other people's thinking.

**Pam **03:36

Yeah, I mean, if you have been the person who has posted your strategy, and someone has commented on it, isn't that amazing?

**Kim **03:41

Yeah.

**Pam **03:41

You get likes and everything. You're like, "Oh! People are reading my strategy! That is so..." We love it when you guys do that. It just builds the whole world up. Ya'll, we post problems on Wednesdays at 7PM Central Time. When you answer tag me and use the hashtag MathStratChat. And join us here to hear how we're thinking about the problem. Thank you for being part of the Math is Figure-Out-Able movement!