# 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 - June 5, 2024

In today’s MathStratChat, Pam and Kim discuss the MathStratChat problem shared on social media on June 5, 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.

**Kim **00:06

And I'm Kim.

**Pam **00:06

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

Alright, this Wednesday, the problem was 3,002 minus 1,905. How would you solve this problem? Go ahead and solve it any way you want, and then listen in.

**Pam **00:32

So, 3,002 minus 1-9-0-5. 1,905. Alright, go. Can I go first?

**Kim **00:39

Sure.

**Pam **00:40

So, I'm going to Constant Difference again.

**Kim **00:43

Okay.

**Pam **00:43

Meaning, I'm going to plunk both those numbers down on a number line and think about how far apart they are but not where they are.

**Kim **00:50

Okay.

**Pam **00:51

I would like to subtract a number that's delightful. And to me, 1,905 is okay, but it's not as delightful as I wish, so I'm going to take that distance down to... I'm going to shift them both down 5. So, the 1,905 becomes 1,900. And the 3,002 down 5 becomes 2,000...I have to think here...97. Ha, I'm alive. I'm awake. Is that right? Yes. That's 5 down. Okay, so now I end up with an equivalent problem. That's funny. Equipment problem a 2,097 subtract 1, 900. No, I don't like that. Look at that. Look at me. Waking up and not liking what I just did.

**Kim **01:31

You want to change? You can change your mind.

**Pam **01:33

Do I get to change my mind?

**Kim **01:34

Absolutely.

**Pam **01:35

Well, now what am I... I got to think about what I'm... Alright, alright, I'm changing my mind. From 1,905. This is thinking live, ya'll, on the podcast right now. I'm going to take 1,905 up to 2000.

**Kim **01:48

Okay.

**Pam **01:48

So, that's 95. That means I have to add 3,002 also plus 95. So, that's 3,097. So, now I have an equivalent problem of 3,097 subtract 2,000. Yeah, like that better. So, 3097 subtract 2,000 is 1,097.

**Kim **02:09

Yeah, I like it. I also like that sometimes you think something is friendly when you shift, and it doesn't end up friendlier, so you just shift again.

**Pam **02:20

Just try it again.

**Kim **02:21

Yeah, totally fine.

**Pam **02:22

Yeah. Yeah, you kind of freed me up that one day when I thought mathematicians could instantly know the best thing to do right off the bat. And we probably do that almost too quickly here sometimes...

**Kim **02:32

Yeah.

**Pam **02:32

...in MathStratChat. But that was real. That was me thinking, "Hey, yeah, I'm just going to turn 1905 into 1900 Sure, that will..." No, that's not good at all."

**Kim **02:40

Yeah, yeah.

**Pam **02:41

Or at least, (unclear).

**Kim **02:41

Well, because the whole point of Constant Difference is to find an equivalent problem that's nicer.

**Pam **02:46

I mean, now that I think about it, 2097 minus 1900. I could still think about the distance between those numbers. Let's just a 1,097 Duh. Like, it's not bad.

**Kim **02:58

It is also very real, people, that we have a microphone in our face. So, (unclear)

**Pam **03:07

So, my brain caught on that one. When I thought about 2,097 minus 1900, I was thinking removal, not distance. But if that distance is just 100 up to the 2,000, right? And then... Or, I mean a 1,000 up, and then 97. Bam! Alright.

**Kim **03:22

Nice. Nice.

**Pam **03:23

So close and yet so far. What are you going to do?

**Kim **03:26

I also want to shift the distance because that's a little funky, but I actually shifted down a little bit. Because the 3,002 just feels so close to 3,000.

**Pam **03:37

Okay. (unclear).

**Kim **03:38

So, I shifted to the left to make the new problem 3,000 minus 1,903. On a number line. I said to the left because I shifted on number line. So, my new problem is 3,000 minus 1,903.

**Pam **03:55

Okay.

**Kim **03:58

And I also found the distance. And, you know, that just feels I Have, You Needy for me, so...

**Pam **04:05

Did you just say I Have, You Needy?

**Kim **04:08

Is that my new phrase?

**Pam **04:09

I think so. That's hilarious. I Have, You Needy. I like. Like, did you just literally go from 1,903 up to 2,000? And that's 97?

**Kim **04:19

Yeah, I think because I went 197 in my head. Like, I started looking at the 1903.

**Pam **04:27

Yeah.

**Kim **04:28

And I went 197. I mean, 1,097 Yeah.

**Pam **04:32

Oh, you can see that 1,000.

**Kim **04:34

Yeah.

**Pam **04:35

I had to see the 97 first, and then the 1000.

**Kim **04:37

Oh, yeah, either way. Okay. Cool. 1,097.

**Pam **04:41

Yeah, so you often will change the first number in a subtraction problem to be a nice number, and then subtract. And that is not my fave. I would prefer to change the second number in the subtraction to be a nice number.

**Kim **04:54

Yeah.

**Pam **04:55

Yeah.

**Kim **04:56

I think a lot of people will. But you could play I Have, You Need some more. Alright.

**Pam **05:02

Sounds good.

**Kim **05:03

We can't wait to see.

**Pam **05:05

So, then I can be I Have, You Needy too?

**Kim **05:09

We need a shirt. I Have, You Needy. Alright people. What are you going to do this week? Join us on MathStratChat. Let us know how you think about the problem, and comment on each other's thinking.

**Pam **05:20

Ya'll, we post the problems on Wednesdays around 7pm Central time. When you answer, tag me and use the hashtag MathStratChat. Then join us here to hear how we're thinking about the problem. Ya'll, thanks for being part of the Math is Figure-Out-Able movement because Math is Figure-Out-Able!